Why do my ovaries hurt during sex?

I have been having unprotected sex with my partner for some time now and for the last two times this week, it had been painful to my female region. i have NEVER experienced this pain before, but i wanted to know if i could be pregnant. My breast have been tender for about two weeks(not worst than regular menstral tenderness) now and im due for my period at the end of the week. I have not experienced any other pregnacy symptoms though. can someone help??