The best time to test for pregnancy is generally from the first day of a missed period. Some very sensitive pregnancy tests can detect pregnancy as early as 4 to 6 days before the expected period, but for the most accurate and reliable result, it is recommended to wait until at least the day of the missed period or even a week after the missed period. Testing too early increases the risk of a false negative result because the pregnancy hormone hCG may not yet be at a detectable level. Testing first thing in the morning is also ideal because the concentration of hCG in urine is highest then.
Key points on when to test:
- Most reliable testing is at the first day of a missed period or later.
- Some tests can detect pregnancy hormone hCG 4-6 days before a missed period, but early tests may be less accurate.
- For irregular cycles, test about 21 days after unprotected sex.
- Testing in the morning improves the chance of an accurate result due to more concentrated urine.
This timing allows the body to build up enough hCG (human chorionic gonadotropin) hormone after implantation, which is what pregnancy tests detect. References:
- Healthline: Best to wait until at least missed period, more accurate one week after missed period
- Clearblue: Some tests detect 4-6 days before missed period but accuracy improves on the day of missed period
- Thomson Medical: Test as early as 10 days after conception but wait till missed period for accuracy
- NHS: Test from day of missed period or at least 21 days after unprotected sex if uncertain cycle
