Hello, I had unprotected sex on August 23rd. I had what I believed to be my period September 10th-13th, with moderate to little bleeding. The period before was August 13th-16th. I am now 9 days late for my period and wondering if I am possiblily pregnant or if it is something else. I have taken HPT and they have come up negative but I do know for some women they can go 3-5 months and still have negative test.