Ok so I was supposed to start my period 30, or 31 of August. I usually start the very end/beginning of month. Well September 1st me and my boyfriend had sex for the first time. He pulled out before he came and nothing got in me, but still there is always a chance. 3 days later I was worried that I still hadn't started my period so I took the plan b. it's now been almost a week since I had sex and It makes me nervous that I haven't started yet. I have had abdominal pain, back pain ( always get this when about to start period, been very tired, and sore breast. Am I ok??