Bleeding After a Positive Test: When to Go In, What a Scan Shows

If the bleeding is light and there is no pain, the right step is to arrange to be seen rather than to rush anywhere - and not to treat it as the answer about how the pregnancy will end, because in the largest cohorts it is not. If there is severe pain, pain on one side, faintness, shoulder-tip pain, or heavy bleeding with clots, that needs looking at now, not in the morning.

The rest of this page is what is actually known: how often this happens, what it can mean, which signs change the urgency, and what the blood tests and scans will and will not tell you, including what is different after IVF.

Any of these alongside bleeding means going to a hospital emergency department, or calling your clinic, straight away:

• Severe pain low in the abdomen or pelvis, or pain on one side
• Pain at the tip of the shoulder
• Feeling dizzy or faint, or collapsing
• Heavy bleeding, or bleeding with clots
• Pain or pressure on opening the bowels
• A racing heartbeat

These come from the symptoms and signs of ectopic pregnancy listed in NICE NG126 1.4.3 and 1.4.4 (pain, bleeding with or without clots, dizziness or fainting, shoulder-tip pain, rectal pressure or pain on opening the bowels, a pulse over 100) and the RCOG's patient leaflet, which adds that the pain may be on one side only and that shoulder-tip pain is a sign the condition is getting worse. NG126 1.4.1 sends women directly to emergency care if they are unstable or there is significant concern about the pain or bleeding.

At or after six weeks, the threshold is lower again: NG126 1.4.9 advises referral for assessment for women with bleeding who have pain, or a pregnancy of six weeks or more, or a pregnancy of uncertain dates. NG126 1.4.2 also warns that ectopic pregnancy often presents atypically, and the RCOG notes some women have no symptoms at all - which is why the appearance of the bleeding is never used to rule it out.

Common enough that it is not, by itself, a signal. Hasan 2010 followed 4,539 women through the first trimester in a community-based study. Bleeding was reported by 1,207 of them - roughly one in four - across 1,656 separate episodes. Only 8 in 100 of the women who bled described any episode as heavy. Most episodes lasted under three days, and most fell between gestational weeks 5 and 8.

A tighter, earlier study points the same way with a smaller number. Harville 2003 followed 221 women with daily urine samples; of the 151 who became clinically pregnant, 14 recorded any bleeding in the first eight weeks, and 12 of those 14 pregnancies ended in a live birth.

The two figures differ because they count different windows and ask in different ways, which is worth knowing before trusting any single percentage on this subject. If the bleeding happened before you had a positive test, the question of whether it was a period or early pregnancy is a different one, and the answer there is that a test settles it and the appearance of the blood does not.

For light bleeding, the honest answer from the best data is no. In the same cohort of 4,539, miscarriage occurred in 12% of the women who bled and 13% of the women who did not - a difference in the wrong direction to be a warning sign.

Hasan 2009 tested it directly on 4,510 of those women, with bleeding in the four days before a loss excluded so that the bleeding of a miscarriage already happening was not counted as a prediction of one. Any bleeding gave an odds ratio for miscarriage of 1.1, with a confidence interval of 0.9 to 1.3 that includes no effect; the authors conclude that spotting and light episodes were not associated with miscarriage, especially if they lasted only one or two days. Heavy bleeding was a different finding: among the 97 women who reported it, the odds ratio was 3.0, from 1.9 to 4.6, and most of that sat in the women whose heavy bleeding came with pain.

There is a real tension in the literature here and it should not be smoothed over. The PRISM trial's own background states that bleeding in early pregnancy is strongly associated with pregnancy loss. PRISM recruited women who had presented at hospital with bleeding; Hasan followed a community cohort in which 92% of those who bled never had a heavy episode. Both can be true of their own populations. What follows for a reader is that heaviness and pain are the features that carry information.

Usually nobody can say for certain on the day, and the scan and blood tests below are how the possibilities get narrowed down. These are the ones a clinician will be thinking about:

• Threatened miscarriage. This is the term for bleeding while the pregnancy is still ongoing. It describes what is happening, not what will happen: NICE NG126 1.9.1 advises a woman with a confirmed pregnancy in the uterus and a heartbeat to return if the bleeding gets worse or lasts beyond 14 days, and to start or continue routine antenatal care if it stops.
• Subchorionic haematoma. A collection of blood between the pregnancy sac and the uterine wall, seen on scan. Across seven studies (1,735 women with one, 70,703 without), miscarriage was 17.6% against 8.9% (Tuuli 2011). In pregnancies conceived through IVF the link was weaker: a 2024 meta-analysis of nine studies found no statistically significant difference in early loss or live birth (Shi 2024).
• Ectopic pregnancy. A pregnancy growing outside the uterus, usually in a fallopian tube - about 1 in 90 pregnancies in the UK, per the RCOG, with IVF and ICSI listed as risk factors. This is the one that must not be missed, and the reason for the emergency list above.
• Implantation. Often suggested, but the evidence is thin. Harville 2003, which pinpointed implantation day from daily urine hormone tests, found bleeding rarely fell on that day and reported no support for the idea that implantation itself causes bleeding. It is not a diagnosis anyone can make from the bleeding alone.

Hasan 2010 also found bleeding was more common in women with fibroids or a previous miscarriage, and that it clustered around weeks 5 to 8, when the placenta takes over hormone production from the ovary. The authors call that consistent with bleeding being a marker of placental dysfunction - a hypothesis about the pattern, not a diagnosis anyone can make from one episode.

NICE NG126 1.5.1 sets the first step: a transvaginal ultrasound to find where the pregnancy is and whether there is a fetal pole and a heartbeat. A scan through the abdomen is offered instead if a transvaginal scan is not acceptable to you, with its limits explained, or if there is an enlarged uterus, a fibroid or an ovarian cyst.

The part nobody prepares you for is that one scan often cannot decide. NG126 1.6.1 says a diagnosis of miscarriage made from a single scan cannot be relied on as fully accurate, and that there is a small chance it is wrong, particularly at very early gestations. Where the crown-rump length measures under 7.0 mm with no visible heartbeat, 1.6.3 requires a second scan at least seven days later before a diagnosis is made. Where no fetal pole is visible and the mean gestational sac diameter is under 25.0 mm, 1.6.6 requires the same seven-day wait, and 1.6.11 says women should be told that waiting for the repeat scan does not harm the pregnancy.

So being sent home to return in a week is not evasion or bad news withheld. It is the guideline, and it exists because scans done too early have been wrong. Separately, for bleeding before six weeks without pain and with no risk factors, NG126 1.4.10 uses expectant management: repeat a urine pregnancy test after 7 to 10 days, return if it is positive, and a negative means the pregnancy has ended.

If the scan cannot yet show where the pregnancy is - called a pregnancy of unknown location - the next step is blood hCG. One number on its own says very little. NICE NG126 1.8.5 asks for two measurements as close as possible to 48 hours apart, and reads the change between them:

• A rise of more than 63% in 48 hours: a developing pregnancy in the uterus is likely, though an ectopic pregnancy is not excluded. A scan is offered 7 to 14 days later, or sooner if hCG is 1,500 IU/L or more (NG126 1.8.7).
• A fall of more than 50%: the pregnancy is unlikely to continue, though that is not yet confirmed; a urine test 14 days later checks it has resolved (1.8.8).
• Anything in between - a smaller rise or a smaller fall - means review in the early pregnancy service within 24 hours (1.8.9).

The 63% figure is a decision threshold, not a description of every healthy pregnancy. In women with pain or bleeding who turned out to have a viable pregnancy, the slowest rise seen was 53% over two days and the typical rise was 124% (Barnhart 2004, 287 women). A later analysis found the minimum rise depends on where hCG starts: 49% below 1,500, 40% between 1,500 and 3,000, and 33% above 3,000 (Barnhart 2016). NICE 1.8.2 is explicit that hCG cannot tell where a pregnancy is - only the scan can.

If you have two results with their dates, the hCG doubling calculator shows how the rise compares with these ranges. It cannot replace the clinician's reading, because the scan findings and your symptoms count for more than the arithmetic - NG126 1.8.3 asks clinicians to put symptoms ahead of hCG results.

Three things change, and one does not. What does not change is the emergency list: pain, faintness, shoulder-tip pain or heavy bleeding mean going in now, whatever the treatment. Symptoms in the days after a transfer are a separate question, covered on their own page.

• Bleeding is more common, and often means less. After hormone-prepared frozen embryo transfers, 149 of 320 women (47%) with a positive test had some bleeding before eight weeks, mostly spotting for a median of two days, and 71% of them had an ongoing pregnancy at 12 weeks against 67% of those who did not bleed (Nielsen 2023). The same paper's review of older IVF studies, which looked at heavy bleeding, did find more miscarriage, so heaviness still matters.
• Ectopic and heterotopic pregnancy need ruling out. In US national data, 1.6% of pregnancies from assisted reproduction in 2011 were ectopic, and 485 of 9,480 ectopics over 2001-2011 were heterotopic - one pregnancy in the uterus and another outside it at the same time (Perkins 2015). NICE NG126 1.7.5 asks the scan to check for exactly this, which is why a scan showing a pregnancy in the uterus does not end the question if pain continues.
• Your dates are exact. NICE 1.6.9 warns against judging a scan by the last period alone because periods vary; after IVF the transfer date and embryo age fix the dates, so a clinic can usually time an early scan more precisely.

Progesterone after IVF is a different situation from progesterone for threatened miscarriage. It is luteal support, and the ESHRE 2025 guideline advises giving it until at least the day of the pregnancy test; how long clinics continue it after that varies. Do not stop or change it because of bleeding without speaking to your clinic. Because spotting is so common in these pregnancies, the amount of bleeding and the presence of pain matter more than the fact of it.

It depends on whether there has been a miscarriage before, and this matters in India because progesterone is prescribed readily for any early bleeding.

PRISM randomised 4,153 women at 48 UK hospitals who presented with bleeding in early pregnancy to vaginal progesterone 400 mg twice daily or matching placebo, through 16 weeks. Live birth after at least 34 weeks occurred in 75% of the progesterone group (1,513 of 2,025) and 72% of the placebo group (1,459 of 2,013) - a relative rate of 1.03, with a confidence interval from 1.00 to 1.07 and a P value of 0.08. Adverse events did not differ significantly.

NICE reviewed that evidence in 2021 and split the answer. For women with a scan-confirmed pregnancy in the uterus who are bleeding and have had a previous miscarriage, NG126 1.9.2 recommends vaginal micronised progesterone 400 mg twice daily, continued to 16 completed weeks if a heartbeat is confirmed (1.9.3); the committee described the evidence of more live births in this group as good. For bleeding with no previous miscarriage, NICE records evidence of no benefit. It also found no evidence of benefit for other progesterone preparations or doses.

So the question to ask is not simply whether to take progesterone, but whether you fall in the group where it was shown to help, and whether the scan has confirmed the pregnancy is in the uterus first - NICE ties the recommendation to that so that it is not given for an ectopic. None of this is a reason to stop medication somebody has prescribed you; it is a reason to ask what it is expected to do. Progesterone in fertility treatment covers luteal support after IVF, which is a separate question with a separate evidence base.

On this subject the gaps are the most useful thing on the page, because they are where false reassurance and false alarm both come from.

• That the colour of the blood means anything. No retrieved study shows that pink, brown or bright red predicts how an early pregnancy ends. Hasan 2009 examined colour alongside duration, pain and timing, and what the risk tracked with was heaviness, and heaviness with pain.
• A single reliable figure for how common early bleeding is. The published range runs from 14 of 151 pregnancies in Harville's prospective cohort to 1,207 of 4,539 women in Hasan's, because they count different windows and ask differently.
• That light bleeding is harmless in every group. Hasan's confidence interval of 0.9 to 1.3 is consistent with no effect and with a small one. It rules out a large effect, not every effect.
• That progesterone helps everyone who bleeds. NICE's 2021 recommendation is limited to women who are bleeding, have a scan-confirmed pregnancy in the uterus and a previous miscarriage.
• That an early scan or a single hCG level can settle the outcome. NICE 1.6.1 states the opposite, and builds repeat scans and paired hCG tests into the pathway for that reason.
• How any of this differs for Indian women. Hasan's and Harville's cohorts were in the United States, PRISM's in the United Kingdom, and every guideline cited here is British. No ICMR or Indian registry data on early pregnancy bleeding was located for this page, so these figures are reported as what they are rather than as national rates.

Bleeding when you badly want a pregnancy to continue is frightening in a way that a confidence interval does not touch, and there is no version of this page that makes the waiting shorter. What can be said is that most early bleeding in these cohorts did not end the pregnancy, that heaviness and pain are the things worth acting on, and that being asked to come back in a week is the protocol rather than a verdict. If a loss has happened before, that changes what gets investigated - and, per NICE, whether progesterone is offered - and is worth raising at the appointment.