A pregnancy test can usually be taken from the first day of a missed period for reliable results. Some very sensitive tests can detect pregnancy a few days before the missed period, but for the most accurate result, it is best to wait at least until the first day of the missed period or even a week after. If you have an irregular cycle, taking the test about 21 days after unprotected sex is recommended to avoid false negatives. Early testing (such as 5 days after intercourse) may not show accurate results since the hormone hCG needs time to rise to detectable levels in urine, typically 7-10 days after ovulation or fertilization.
In summary, it is advisable to take a pregnancy test:
- On the first day of a missed period for most accurate results
- Up to a week after the missed period for confirmation
- At least 21 days after unprotected sex if menstrual cycles are irregular or periods are not tracked
