Is it normal for your period to stop right after insertion?

I got the mirena IUD inserted almost 6 weeks ago and I haven’t had any spotting or bleeding since (about 17 days late for when it should’ve been my period). I know sometimes people stop having their period on the IUD but is it normal for bleeding to stop this fast? Am i really lucky or should I be taking a pregnancy test? I waited for the recommended 7 days before having sex after insertion if it makes a difference