I NEED HELP/ADVICE!

Mehgan

So, I have had the IUD (Mirena which is over 99% effective l) for over a year now (about a year and 2 months to be exact), my boyfriend and I had unprotected sex for the first time last night and he finished in me, should I get a plan B just in case? Im feeling crampy (which I do get occasionally) but, it could just be indigestion or something. Any who, I need opinions on whether or not I should take a Plan B or not?