How to Confirm Your Pregnancy: Home Tests and Blood Tests
Am I Pregnant? How to Know for Sure
You have waited and waited, your body feels like it is changing, and you are eager to find out whether that sneaking suspicion is correct. So you ask yourself, am I pregnant? Many women planning to become pregnant keep a stash of home pregnancy tests on hand, and that is not a bad idea since they are quite accurate when used correctly.
How Pregnancy Tests Work
Pregnancy tests return a result based on the level of the hormone HCG (human chorionic gonadotropin) which is released into the bloodstream soon after conception, initially at very low levels but increasing rapidly until about twelve weeks into the pregnancy.
- Around 5% of women will return a positive result from a home pregnancy test as early as 8 days into the pregnancy.
- Most experts recommend waiting at least 14 days past the likely conception date.
- An early positive result from a urine sample can be confirmed with a blood test from around 10-12 days after conception.
- Testing too early may give a negative result even though you may still be pregnant.
- An early positive result should be rechecked around 14 days after conception to ensure accuracy.
Home Pregnancy Tests: How to Use Them
There is a wide range of home pregnancy tests on the market that test for HCG levels in urine. If you follow all instructions, the tests are approximately 97% accurate. More sensitive tests detect anything over 20 MIU per ml, giving results from as early as 8 days after conception. Most tests detect around 50-100 MIU per ml before returning a positive result.
- Best testing time: First thing in the morning when hormone levels are most concentrated, though most modern tests work any time of day.
- Avoid excess water: Do not drink lots of water before testing to prevent diluting the urine.
- Read instructions carefully: When anxious or excited, it is easy to get mixed up. Take a deep breath and stay calm.
- Time the test precisely: Use a watch with second hands and check results within the recommended time limits.
- Collection tip: Consider collecting urine mid-stream in a container, then dipping the test in to reduce the risk of missing.
- Reading results: One line (control) means not pregnant; two lines mean pregnant. Watch for evaporation lines that can cause confusion.
Blood Tests for Pregnancy Confirmation
Blood pregnancy tests are estimated to be more than 99% accurate and test for HCG. Some tests check the HCG level to indicate how far along the pregnancy has progressed. A blood sample is sent to a pathology laboratory with results available in a day or two. However, urine-based tests have become so accurate that blood tests are rarely needed to confirm pregnancy anymore.
Understanding False Positive Results
False positive results are rare but can be heartbreaking. A test may say you are pregnant incorrectly for these reasons:
- Chemical pregnancy: A term for a very early miscarriage. About half of all pregnancies are thought to end in miscarriage shortly after conception. A test taken very early when HCG levels have started to climb may detect a positive response before a period occurs.
- Not following directions: A test that has been sitting around too long beyond the specified reaction period may return a false positive.
- Fertility treatments: Some treatments contain HCG hormone and may return a false positive if the hormone is still present.
Understanding False Negative Results
If you test too early, you may get a negative result even though you are pregnant. Testing a few days later may give a different result, so monitor changes in your body. In rare cases, a pregnancy test may not be working properly, requiring a retest.
| Test Type | Accuracy | Sensitivity (MIU/ml) | Results Time | Earliest Detection |
| Sensitive Home Test | ~97% | 20+ MIU/ml | Minutes | 8 days after conception |
| Standard Home Test | ~97% | 50-100 MIU/ml | Minutes | 14 days after conception |
| Blood Test | 99%+ | Detects all HCG levels | 1-2 days | 10-12 days after conception |
