If you are 4 weeks and 5 days pregnant, it is generally recommended to wait until you have missed your period before taking a pregnancy test. This is because at this stage, the levels of hCG (human chorionic gonadotropin) in your body may not be high enough to be detected by a home pregnancy test. Waiting until you have missed your period will increase the accuracy of the test results. However, some early detection tests claim to be able to detect pregnancy as early as 6-8 days after ovulation. These tests are more sensitive and can detect lower levels of hCG in your urine. If you decide to take an early detection test, make sure to carefully follow the instructions provided with the kit for accurate results. It's important to note that even if you get a negative result on an early detection test, it doesn't necessarily mean you're not pregnant. If you still suspect that you might be pregnant after getting a negative result, it's best to wait a few more days and retest or consult with your healthcare provider for further guidance.