[Lizzie]

A test would only be accurate if it has been at least fourteen days since you have had sex. So you need to wait until at least the two week mark. If it has been two weeks an over the counter pregnancy test should give an accurate reading.

There are so many different things this could be, its impossible to tell just by a description over the internet. A pregnancy test is really your best option at this point. If it comes up negative and you are still having irregularities with your period you should probably speak to your doctor. There are things they can do to help get you on a more regular cycle.