Home Pregnancy Tests and hCG

Here's What You'll Find Below:  • Average range of HcG levels
  • Not all pregnancy tests are created equal
  • When can I take a test?
  • How does a positive result look?
  • Is it possible to receive a false positive?

by Courtney Sullivan

When a women becomes pregnant her body starts to produce a hormone called hCG (Human Chorionic Gonadotropin) This hormone give the positive result on both urine and blood based tests. hCG is produced by the embryo at implantation (when it starts to implant itself into the utering lining.) Implantation occurs 6-10 days after conception. As the embryo grows, the amount of hCG increases and doubles approximately every 2-3 days. The purpose of this hormone is to keep estrogen and progestone levels in proper balance until the placenta is adequately developed. Levels peak at 10 - 12 weeks at a level as high as 300,000 mIU/ml and then drop off.

Average Range of hCG Levels

Pregnant women will vary in levels of hCG within their body at different times. But once hCG levels beginning to build, they should not fall until after 10 - 12 weeks (LMP). A dramatic decline in hCG levels may indicate a miscarriage" and one should consult with their caregiver. The chart below gives an average range of mIU/ml of hCG in pregnant women from 3 - 26 weeks from last menstrual period. Please note that in multiple births hCG levels may raise faster. An hCG level of less than 5 mIU/ml generally indicates you are not pregnant.

Weeks from Last
Menstrual Period (LMP)
Amount of hCG
in mIU/ml
3 5 - 50
4 4 - 426
5 19 - 7,340
6 1,080 - 56,500
7 - 8 7,650 - 229,000
9 - 12 25,700 - 288,000
13 - 16 13,300 - 254,000
17 - 24 4,060 - 165,400
25 - 40 3,640 - 117,000

Pregnant women usually attain serum concentrations of 10 to 50 mIU in the week following conception. A maximum is reached by the second to third month, followed by a decrease in the third trimester.

Pregnancy Tests

Not all pregnancy tests are created equal. The more sensitive the test (the smaller amount of hCG it can detect), the earlier the opportunity to detect pregnancy. That means with a test sensitive to 20 mIU/ml hCG, a home pregnancy test is accurate as early as six to eight days after conception, well before your first missed period. NOTE: Conception may take place several days after date of intercourse, so the date of intercourse should not necessarily be viewed as the day of conception.