I don't know the exact date of my last period, but I believe it was around August 18th. I've always had a very irregular cycle, going anywhere from 3 to 6 weeks between periods. I had unprotected sex and my boyfriend came inside me on September 11th & 15th. I have several questions. What are the chances that I am pregnant?? At what point, if I don't get my period, should I take a pregnany test (& the results be accurate)?? Is it possible that I might get my period anyway, and still be pregnant? I've read that it is possible, but it's usually an irregular period. Mine are usually fairly light & only last about 3 days. What might be different if I am still pregnant? Also, I can usually tell when I am about to start, I get really awful cramps for about a week before hand. I have not had this at all or any other signs that I might be getting ready to start my period, or that I might be pregnant. Except that I have had to pee a lot. Any information and advice would be helpful, thanks!