Pain During Sex

So I’ve been sexually active for about two years now, and while I’ve always experienced some pain with different positions, with my new partner it’s gotten a bit out of hand. Now I can’t do anything outside of missionary without experiencing extreme pain, and sometimes even that position hurts. It’s not a size issue because past partners weren’t as much of a problem. I don’t know if I should see a doctor or if it’s something I can resolve on my own. 😕