Quick question and opinions.

So yesterday morning I just got off my period. I don’t get these often because I have had an IUD Mirena for nearly a year now and that can stop you from having periods and stuff. Last night I had unprotected sex.. I know that the mirena stops you from getting pregnant but I just need a little bit of closure 😂 I think I’m just over thinking abit. You can’t get pregnant when you have the Mirena right?