Mirena - need to use condoms too?

Quick backstory! Been on the minipill for 5 Years but definitely wasn’t doing me any favours. Been with my fiancé for all of that time and have always used a condom as well. I heard about the mirena and got it the other day, when it’s effective I want to be able to not use condoms because I think it’ll just be a bit nicer but I’m so paranoid about getting pregnant! I don’t have to worry about STDs because we have only ever slept with each other but we’ve always used condoms so it might be weird. Should I just keep using them? Or will I be okay without?