Me & my bf had unprotected sex on a Sunday. He grabbed his penis so he wouldn't c*m in me, but wasn't that sure none got inside me. I was supposed to ovulate that day according to my calendar but I know it can be slightly off. I took Plan B One-Step around 2 o'clock Tuesday. I was wondering if I should be worried? I know stress can delay a period too. I am having slight cramps but that's pretty much it!