After Sex

Hannah
I'm not sure if anyone else gets this but usually after sex, I get a horrible pain in the area between the anus and the vagina that can last either a couple of hours or a few days. 
I thought that maybe it could be friction burn but I'm not entirely sure as we usually lube up the area and the penis really well. 
I was wondering if anyone knows why this happens and if they get it too and what you guys do to prevent it or make it less painful?