I am 19 years old and my periods have always been exactly 28 days. This month I was supposed to get it on Thursday but I got it Sunday morning. I had really bad cramping that kept me up all night, lower back pain, over emotional, and recently have been craving salty foods more than usual. I am not under any stress, my daily activities haven't changed, and I have been relaxed as of late. I had my last period Jan 1, so i was ovulating around the 14th, and i had sex a few days before then, that day, and after that day. We used protection some times, but others we were unprotected. He pulled out and definitely didn't *** in me (sorry tmi). Is my cycle changing for no reason? Am I pregnant?