Last month me and my boyfriend had sex and he comed in me. A couple of weeks later when my period was due it didn't come and then when December 1st came around while i was at school i felt like i was on my period i mean i had light cramps every now and then. Later on that night i got my period and my cramps are really bad not like they normaly are. Also in that time period my diet changed on me i mean usually i can't eat a lot but i started to eat more than i regularly do and i am active in sports but my period has never changed like this before. so I was wondering if it could be signs of pregnancy.