hCG Levels by Week: Chart, Doubling Time and What the Numbers Mean

hCG levels rise fast in early pregnancy, roughly doubling every two to three days, peak around week 10 and vary so widely that no single number can date or diagnose a pregnancy.

Staring at a “beta hCG” number in your lab portal? Below are the hCG levels by week ranges published by Cleveland Clinic and by MedlinePlus (the National Library of Medicine). They do not match each other, which is the first thing to know about hCG levels.

Every figure here was read on a primary medical source in October 2026 and is attributed. What this page cannot do is tell you what your own result means. Only your clinician can, using your dates, symptoms, repeat tests and ultrasound.

What Is hCG?

MedlinePlus says your body starts making hCG when a fertilized egg attaches to the wall of the uterus. StatPearls, a clinical reference hosted by the National Institutes of Health (NIH), names the source: trophoblast tissue, part of the early embryo that later becomes part of the placenta. hCG supports the corpus luteum, which sustains progesterone production. Results are reported in mIU/mL.

When hCG Shows Up in Blood vs. Urine

• Blood: a blood test can show a pregnancy before a missed period (MedlinePlus). Lab tests detect hCG as low as 1 to 2 mIU/mL (StatPearls).
• Urine: tests typically turn positive at 20 to 50 mIU/mL (StatPearls). MedlinePlus rates home tests 97 to 99 percent accurate a week or two after a missed period.
• Qualitative test: a yes or no: is hCG present?
• Quantitative (beta hCG) test: the exact amount, used for the chart below and to follow a pregnancy over time.

Reference points: MedlinePlus lists under 5 mIU/mL as normal for non-pregnant women and under 2 for healthy men. Cleveland Clinic says a level above 25 usually means you are pregnant. A result in between does not settle the question, which is one reason tests are repeated.

hCG Levels by Week Chart (Weeks From Last Menstrual Period)

The first column is from Cleveland Clinic, which counts weeks since the last menstrual period (LMP). The second is from the MedlinePlus entry on the quantitative hCG blood test, which lists ranges by week of pregnancy.

• The ranges are enormous: two healthy pregnancies on the same day can be thousands of units apart.
• The sources differ: and neither is wrong. MedlinePlus says normal ranges vary among laboratories, and Cleveland Clinic calls its numbers “just a guide.” Use the range on your own lab report.
• One number is not a diagnosis: it cannot date a pregnancy, show whether it is in the uterus or predict how it will turn out. Being a few days off on your dates moves you to a different row.

hCG Doubling Time in Early Pregnancy

• Mayo Clinic: hCG doubles every 2 to 3 days in early pregnancy.
• MedlinePlus and Cleveland Clinic: it almost doubles every three days for the first 8 to 10 weeks.
• StatPearls: gives a faster figure, about every 24 hours for the first 8 weeks.

The sources disagree, so do not grade yourself against one rule. Clinicians use a minimum, not an average: per the StatPearls review of ectopic pregnancy, when the first level is under 1,500 mIU/mL, 99 percent of viable pregnancies in the uterus rise at least 49 percent over 48 hours. A healthy pregnancy can rise more slowly than “doubling in two days.”

The rise also slows as levels get higher: that minimum applies to low starting values, and the rapid climb ends by 8 to 10 weeks (Cleveland Clinic). Because ranges vary among labs, ask to repeat tests at the same lab, and let your provider do the math.

When hCG Peaks and Declines

Cleveland Clinic and StatPearls place the peak at around 10 weeks. StatPearls adds that levels then decrease until about week 16 and stay fairly constant until term, so a lower number later on is the expected pattern. By then, care has moved to ultrasounds, and you may be reading about your pregnant belly by month, pregnancy announcement ideas, or baby girl names, baby boy names and gender neutral names.

What Low or Slow-Rising hCG Levels Can and Cannot Mean

• The dates are off: Cleveland Clinic lists miscalculated dating, and notes that healthy pregnancies may have lower-than-average hCG.
• Early pregnancy loss: MedlinePlus lists incomplete or threatened miscarriage and fetal death. Cleveland Clinic adds blighted ovum.
• Ectopic pregnancy: a pregnancy outside the uterus, about 1 to 2 percent of U.S. pregnancies (StatPearls).

StatPearls notes that a slower rise, or a drop of at least 21 percent over 48 hours, is more indicative of miscarriage or ectopic pregnancy. But a low number cannot say which, or whether anything is wrong at all. Cleveland Clinic says your provider will test again in a few days, and an ultrasound often follows. If waiting is wrecking your sleep, see our guide to melatonin while pregnant.

What High hCG Can Mean

• Further along than you thought: the first reason on Cleveland Clinic’s list.
• More than one baby: listed by MedlinePlus, but no source we reviewed gives an hCG number that identifies twins. Ultrasound answers that.
• Molar pregnancy: a hydatidiform mole is a rare growth that forms in the uterus at the start of a pregnancy, found by hCG testing plus ultrasound (MedlinePlus).
• Rarely, certain tumors: MedlinePlus lists choriocarcinoma and ovarian cancer.

StatPearls is careful here: hCG above 100,000 mIU/mL in early pregnancy is highly suggestive of a complete mole, although many normal pregnancies reach that level at their peak around weeks 8 to 11. A high value alone is never a diagnosis.

hCG and Ultrasound: The Discriminatory Zone

hCG confirms a pregnancy before ultrasound can see it. Per StatPearls, the first sign in the uterus, a small sac, typically becomes visible during the fifth week. The “discriminatory zone” is the hCG level above which a pregnancy in the uterus should be visible on transvaginal ultrasound. Historically set at 1,000 to 2,000 mIU/mL, it is now placed as high as 3,500 by the American College of Obstetricians and Gynecologists (ACOG), StatPearls reports, to avoid misdiagnosing a viable pregnancy. It varies with the equipment, the sonographer and the number of babies. It is a clinician’s tool, not a cutoff for reading your own result.

hCG After Miscarriage or Birth, and When You Are Not Pregnant

After a delivery or the end of a pregnancy, hCG typically takes 7 to 60 days to return to zero (StatPearls), so a home test can stay positive for a while. Mayo Clinic notes that a positive can follow a loss soon after implantation. After a molar pregnancy, hCG is monitored, and MedlinePlus says to avoid pregnancy for 6 to 12 months so testing stays accurate.

People who are not pregnant have very little hCG. StatPearls notes that small amounts come from the pituitary gland, liver and colon, and that levels rise with age: a cutoff of 14 mIU/mL has been suggested for women over 55. Because certain tumors raise hCG, the test is also used outside pregnancy (MedlinePlus).

What Affects a Home Pregnancy Test

• Testing too early: the main cause of a false negative (MedlinePlus).
• Dilute urine: do not drink large amounts of fluid first. Morning urine usually has more hCG (MedlinePlus).
• Reading too soon: use a timer (Mayo Clinic).
• Fertility medicines containing hCG: including trigger shots, a cause of false positives (MedlinePlus, Mayo Clinic, StatPearls). Ask your clinic when to test.
• Recent loss, menopause or ovary problems: possible false positives (Mayo Clinic).
• The hook effect: rare. At extremely high hCG, about 500,000 mIU/mL, a test can read falsely negative. StatPearls raises it with gestational trophoblastic disease such as molar pregnancy, where labs dilute the sample.

What does not: Mayo Clinic says most medicines, including antibiotics and birth control pills, do not affect home test accuracy. Biotin is not named by any source below as a cause of a wrong home pregnancy test. Still, tell the lab what supplements you take.

Related Betteroo Guides

• Pregnant belly by month
• Signs of leaking amniotic fluid vs. discharge
• What do contractions feel like?
• Pregnancy announcement ideas
• Can you take melatonin while pregnant?
• Baby girl names

When to Call Your Provider

Call your provider’s office if:

• You have a positive home test and no prenatal appointment yet (Mayo Clinic).
• You have questions about an hCG result (Cleveland Clinic).
• You have light vaginal bleeding or pelvic pain in early pregnancy, often the first warning signs of ectopic pregnancy (Mayo Clinic). Call the same day. Do not wait for your next lab result.

Call 911 or go to the emergency room for the ectopic emergency symptoms Mayo Clinic lists, whatever your hCG number:

• Severe abdominal or pelvic pain with vaginal bleeding
• Extreme lightheadedness or fainting
• Shoulder pain

Later in pregnancy, know the signs of leaking amniotic fluid and what contractions feel like. This page is general education, not medical advice.

Frequently Asked Questions

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