[Harmony♥]

Any time you have sex, there is going to be a chance of pregnancy. Just because you've had your period doesn't mean that you're in the clear. You can take a pregnancy test up 14 days after unprotected sex, and it should give you a clear result, though it's always best to wait until you've missed your period. Since you mentioned your periods aren't always regular, you may want to wait 14-21 days after you last had unprotected sex and take a test. Make sure to take it first thing in the morning, when you are more apt to getting an accurate result.