Pregnant on IUD?

I’ve had my mirena in place since November 2022 and haven’t have a period since. At the end of June I had some slight spotting which I didn’t think anything of until today. Since then I have had extremely tender breasts, food aversions, slight nausea and today I noticed wet patches on my top where my breasts had leaked slightly. This is what’s made me put everything together and now I’m concerned a may be pregnant.

I am planning on going out first thing to buy a test but how likely is it I’m pregnant? Has this happened to anyone else on the mirena? I have 3 children already and have recently started a new job, this is causing me to panic extremely 😅

Any help/advice would be much appreciated