Pain/period

So lately, whenever my boyfriend and I try to have sex it's really painful for me. It doesn't even go in all the way before I have to stop cause it hurts.  I was due to get my period a week ago but haven't had any signs for getting it. All that's been happening is a little white discharge. I don't know if the pain has something to do with my period about to start or if it's something else. Help!?