Every once in awhile when I have sex with my SO I find out little bit into it that in bleeding/spotting a bit. It's not lots of blood and it stops quickly. This time it happened and is about a week before my period but I don't know if that has been the same with the time before. I'm not new to sex so I'm sure that's not the reason. I just feel really bad when it happens cause it stops all the fun and the feelings. Just always seems to wreck the night. Not sure what to do or what's causing it. Any wisdoms, ideas or suggestions?