Usually, I always get my period the last week of the month. However, the last time this occurred was April 24-29. For some reason, I did not get my period the month of May but instead two weeks later from the 17th-23rd of June. I want to take a pregnancy test that detects up to 6 days before my period is supposed to start (first response early result pregnancy test) but I'm not really sure when to expect my next period..