My stomach has been feeling bloated, my lower back aches that also goes to the sides of stomach. I'm always super tired and not in the mood to do anything, this morning I had a running nose, had the chills and a stomach ache, my boobs would hurt every now and then. I've been feeling very slow and heavy. Boyfriend and I had unprotected sex a couple of times but I've been on birth control pills. Forgot to take one next morning of unprotected sex. Took 2 HPT, both negative. Why else could this be happening?