Vagina pain

Okay so I have never had any problems in the bedroom before now but recently I am having real troubles. So I have a new boyfriend of 3 months now and sex has always been fine but the last few weeks it has become very painful to have sex. Every time there is such pain that I cannot even let him put it in without bad pain instantly. Some times it causes bleeding. I have an IUD and I have checked and it hasn’t moved it still feels in place. Any idea what it could be or what I can do! Sorry for the TMI