I had unprotected sex on March 28th. My period usually starts on the 10th-11th of every month.

Ideally, on or after your period should have started. By then, almost all pregnancy tests will give you an accurate answer. Some tests claim to tell you up to a week before your period is due to start, but accuracy declines the sooner you do the test.

I had unprotected sex on March 28th. My period usually starts on the 10th-11th of every month.

During your period, or the time you're supposed to start.