HELP!! Feeling pressure while having sex?

Ok, I'm 19 and I've only had sex like 3 times. The last time I had sex I felt a deep pressure inside during sex. Like it hurt but then again it didn't hurt (if that makes any sense at all). It was just a little uncomfortable and somewhat pleasurable, otherwise I would've completely enjoyed it. I was just wondering if this is normal and is something to expect every time I have sex or if it will go away eventually.