You can test if you're pregnant as early as 4 to 6 days before your expected period using very sensitive early detection pregnancy tests that detect the hormone hCG in your urine. However, the most reliable time to take a pregnancy test is from the first day of your missed period, when the hormone levels are higher and results are over 99% accurate. If you test early and get a negative result, you may still be pregnant because hCG levels might not be high enough to detect yet. Testing again on the day your period is due or a few days after is recommended for the most accurate result. The best time of day for early testing is with your first morning urine, as it contains the highest concentration of hCG. If you do not know when your period is due or have irregular cycles, waiting at least 21 days after unprotected sex for a pregnancy test gives more definitive results. In summary:

• Earliest testing: about 4-6 days before missed period with sensitive tests.
• Most accurate testing: from the first day of missed period onward.
• For irregular cycles or uncertainty: test 3 weeks after unprotected sex.
• Test with first morning urine for early testing accuracy.

This guidance gives you the best chance to detect pregnancy early and accurately.