First time

I have been dating my boyfriend for about five months now and lately I've been thinking that we could be ready to go all the way. We are both 20 years old and virgins and have been experimenting with each other sexually for a few months, but have been saving sex for when we're both 100 percent ready. We are open with each other and have no problem talking about birth control or anything like that. Anyway, I've felt ready to go all the way with him for a while now and he's said/ done things lately that make me think he might be ready too. I would love to know what to expect during my first time. I would be on the pill and he would wear a condom, but I am concerned about the level of pain I might feel and how to make sure we're both relaxed so we can enjoy such a special moment. What should I expect?