Copper IUD

Hi, I am late on my period by a day so far. The app tells me when my period is to start. Pretty accurate but sometimes it's off but not by much. I always start before what the app tells me or day of. Never later but I have the copper IUD and I know it's super hard to get pregnant on it. I've I had it in 5years and the doctor told me it was good for 10. Could I be pregnant? I don't feel my period coming on like usual. Usually a day or 2 before I start cramping but nothing. I'm just curious if anyone here has gotten pregnant on this or knows what I should do. My past period was june 21-25 and before that was may 29-2. I usually go 2-3 weeks between periods.