Sorry for the TMI pic!

Me and my fiancè had sex and he finished in me last week. I had some weird belly feelings (not like cramps) for a day so i put a pad in incase but then i went loo and had blood on the pad. I'm probably being really stupid right now but my period isnt due for a week but i'm really confused. I know it sounds really dumb but I'd rather be safe and have a idea than not :)