You can check hCG levels two ways: with a home urine test that gives a yes-or-no answer, or with a blood test ordered by a healthcare provider that measures your exact hCG concentration in mIU/mL. Which method you need depends on whether you’re simply confirming a pregnancy or tracking how levels change over time.
Urine Tests vs. Blood Tests
Home pregnancy tests detect hCG in your urine and are about 97% accurate when used correctly. They work by reacting to hCG above a certain threshold, but they only tell you whether the hormone is present, not how much. Most are designed to be used on or after the first day of a missed period, roughly two weeks after conception.
Blood tests come in two forms. A qualitative blood test gives a simple positive or negative, similar to a home test. A quantitative blood test (often called a “beta hCG”) measures the exact amount of hCG in your blood, reported as mIU/mL. This is the test your provider will order when they need to monitor how your levels are rising or falling, such as in early pregnancy, after a loss, or during fertility treatment. No fasting or special preparation is needed for a blood draw.
Blood tests can detect pregnancy earlier than urine tests. HCG begins building after the fertilized egg implants in the uterus, about six to ten days after conception. A blood test can pick up very small amounts within seven to ten days, while most urine tests need about ten days to register a positive.
Not All Home Tests Are Equally Sensitive
Home pregnancy tests vary dramatically in how much hCG they need to trigger a positive result. First Response Early Result is the most sensitive widely available option, detecting hCG at roughly 6.3 mIU/mL. That’s sensitive enough to catch over 95% of pregnancies by the day of a missed period. Clearblue Easy Earliest Results detects at 25 mIU/mL, picking up about 80% of pregnancies at that same point.
Many other store-brand and budget tests require 100 mIU/mL or more before they show positive. At the level present on the day of a missed period, those tests detect only about 16% of pregnancies. If you’re testing early, the brand matters. If you get a negative but your period still hasn’t arrived a few days later, test again. HCG roughly doubles every two days in early pregnancy, so a test that was negative on Monday could easily be positive by Wednesday or Thursday.
Normal hCG Levels by Week
If you get a quantitative blood test, the number on its own doesn’t tell you much without context. Normal ranges are extremely wide, and what matters more than any single number is the trend over time. That said, here are the reference ranges published by UCSF Health, measured from the first day of your last menstrual period:
- 3 weeks: 5 to 72 mIU/mL
- 4 weeks: 10 to 708 mIU/mL
- 5 weeks: 217 to 8,245 mIU/mL
- 6 weeks: 152 to 32,177 mIU/mL
- 7 weeks: 4,059 to 153,767 mIU/mL
- 8 weeks: 31,366 to 149,094 mIU/mL
- 9 weeks: 59,109 to 135,901 mIU/mL
- 10 weeks: 44,186 to 170,409 mIU/mL
- 12 weeks: 27,107 to 201,165 mIU/mL
Notice how wide these ranges are. At six weeks, one healthy pregnancy might show 152 mIU/mL while another shows 32,000. A single number that falls within range is reassuring, but a single low or high number isn’t automatically cause for concern. Your provider will almost always want at least two draws, spaced 48 hours apart, to see the direction your levels are heading.
What “Doubling Time” Means
In a healthy early pregnancy, hCG doesn’t need to literally double every 48 hours. The minimum expected rise depends on your starting level. When hCG is below 1,500 mIU/mL, providers look for at least a 49% increase over two days. Between 1,500 and 3,000 mIU/mL, the expected minimum drops to about 40%. Above 3,000, a 33% rise is considered adequate. Some researchers have set the floor even lower, at 35% over two days for a viable pregnancy.
As pregnancy progresses and hCG climbs into the tens of thousands, the rate of increase slows naturally. Levels typically peak somewhere between weeks 8 and 12, then gradually decline for the rest of pregnancy. A slowdown after the first trimester is completely normal.
When hCG Patterns Raise Concern
Providers order serial hCG draws (two or more blood tests over several days) when they need to distinguish between a healthy pregnancy, a miscarriage, and an ectopic pregnancy. The patterns can overlap, which is why this requires careful interpretation.
In ectopic pregnancies, hCG typically rises more slowly than in a normal intrauterine pregnancy. Research published in Fertility and Sterility found that the median two-day increase in ectopic cases was about 27%, compared to about 52% in viable pregnancies. When ectopic hCG levels were falling, they declined by about 22% over two days, slower than the roughly 32% drop seen in completed miscarriages. Importantly, about 35% of women with ectopic pregnancies had hCG patterns that looked fast enough to mimic a viable pregnancy, and 20% of those with declining ectopic levels showed a drop that mimicked a miscarriage. A “normal looking” rise or fall does not rule out an ectopic pregnancy on its own, which is why providers combine hCG tracking with ultrasound.
hCG Monitoring After IVF
If you’re going through IVF, your clinic will schedule your first blood draw (the “beta”) at a set number of days after embryo transfer, typically around nine days for a frozen transfer. The number at that first draw carries real predictive weight. Research on single frozen embryo transfers found that when hCG was below 26.5 mIU/mL at nine days post-transfer, half of those pregnancies ended in early loss. When the first level was above 100 mIU/mL, nearly 90% continued as ongoing clinical pregnancies.
Your clinic will likely schedule a second draw two to three days later to confirm the level is rising appropriately before moving on to an early ultrasound.
How Long hCG Stays in Your System
After a miscarriage, hCG drops faster than many people expect. A 2013 study of 443 women found a 35 to 50 percent reduction within two days of the pregnancy resolving, and a 66 to 87 percent reduction by one week. Even with that steep decline, enough hCG can linger to produce a positive home pregnancy test for a week to several weeks afterward.
If you’ve received an hCG injection as part of fertility treatment (trigger shots like Pregnyl, Profasi, Novarel, or Ovidrel), the injected hormone typically takes about 10 days to clear from your body. Testing before that window closes can give a false positive.
What Can Affect Your Results
Fertility medications containing hCG are the most common cause of a false positive on both blood and urine tests. Several other medications can also interfere, including certain antipsychotics, the anti-seizure drug carbamazepine, some anti-nausea medications, and progestin-only birth control pills. If you’re taking any of these and get an unexpected positive, let your provider know so they can verify the result.
Testing too early is the most common cause of a false negative. If you test before implantation is complete, there simply isn’t enough hCG circulating to detect. With urine tests, diluted urine (from drinking a lot of water) can also push hCG below the test’s detection threshold. Testing with your first morning urine gives the most concentrated sample and the most reliable result.