Do I need to get “used” to sex?

So me and my bf had sex for the time a while ago, and it was the first time for the both of us. The first time hurt a tiny bit for me at first, but it faded by the end. We’ve since had sex about 1-2 more times, and it’s not super painful when he first goes in but it’s uncomfortable for the first minute? What I mean is, the “stretch” at first takes me a minute to get used to before I can let him keep going.

I guess my question is, is this normal/common?