I have a question for those of you who are sexually active.

I'm going to keep this brief, because it isn't exactly a comfortable subject to talk about. I've been sexually active for less than a year, maybe 7 or 8 months. I lost count of the times I've had it because my fiance and I have sex regularly, but I'm just now noticing a bit of a change. He isn't extraordinarily large, probably about average, and usually afterwards I would tighten up again. Obviously never to the point that I was before losing my virginity, but relatively close. I had sex yesterday and I'm noticing this morning that I still haven't really closed up at all down there. Is this normal, or should I be concerned?