Have an IUD but the condom broke

So I’ve been having sex with this guy for a couple months now and today we had sex and I noticed after a few minutes when I went to pee that the condom broke and I saw some white liquid in the toilet so I told him it broke and he went to buy plan b for me and I took it the same day after like 20 minutes after but I do have an IUD I’m pretty sure I have the mirena but I don’t quite remember because I haven’t gone to get it checked in about 5 months but I do have an appointment to check it tomorrow. Anyway should I be worried about getting pregnant because I really don’t want a kid right now, I already have a 1 year old and I’m not ready for another one.