S E X GONE WRONG

I had sex with my boyfriend last night, and something weird and never before happened.. 5 mins into it we had to stop cause we thought we heard my mom he pulled out and there was thick white milky stuff around and all over him. I'm not due for my period for another week and I have been having cramps and been insanely tired I had to miss class yesterday due to that, WTF IS HAPPENING. I've honestly never had this happen to me. Advice?