Sex painful?

Abit of a tmi but I am 34 weeks pregnant and my SO and I were fooling around, he was using my dildo on me and it was feeling good per usual, I was soaking wet by the time we got into having sex and oh man it hurt when we started. I've never experienced pain during sex with him before, i had to pull his member out twice due to this odd pain, anyone know what could of caused this? I am a high risk pregnancy if that makes a difference. now I am experiencing a lot of pressure in my vagina