Is this normal?? Sorry very TMI!!!

Sorry very TMI!!!

But I noticed that the very opening of my vagina, right when you go in, is very hard and my vagina feels tighter. I haven't had sex in a month and I haven't had anything in there until right now.

Is there a reason why is feels so hard? It's not my cervix just right inside my vagina feels harder and it's a little harder to open. It almost feels like a bone at the top I guess? Maybe I just never noticed before.