My boyfriend and I had unprotected sex on January 1. January 5, I went to urinate at 2:25pm and after I clean myself, I saw light, pinkish blood on the toilet tissue. When I used the bathroom again around 4, there wasn't any blood and when I used the bathroom around 7:30pm, there was that light red/pinkish blood again. My last period started on December 17 and lasted until December 20 so I am in my ovulating cycle and my period isn't due until January 17. Yes, it is possible for my body to change and my period would come on early but my menstrual cycle never really change. What could this be? I am cramping at the moment and its making me feel sick. I would be disappointed if I am not pregnant but we could always try again. We are expecting to move in together after I graduate undergrad in May and get marry when I complete my masters. Any ideas and advice would be helpful.