You can take a pregnancy test as early as a few days after a missed period, but the accuracy of the test may vary depending on the type of test you use and your individual circumstances.

Most home pregnancy tests detect the presence of human chorionic gonadotropin (hCG), a hormone produced by the placenta after implantation occurs. Implantation usually occurs about 6-12 days after fertilization. However, the level of hCG may not be detectable in urine until several days after implantation.

Therefore, it's generally recommended to wait at least a week after a missed period before taking a home pregnancy test for accurate results. If you take the test too early, you may get a false negative result, which means that you are actually pregnant but the test did not detect the hormone yet.

If you're unsure about the timing of the test or have any concerns, it's best to consult with a healthcare professional who can provide personalized advice based on your specific situation.