Could I be pregnant?

Little info, I am married and have had the skyla IUD for just about 3 years and am getting ready to get it replaced. Throughout the years it's made my periods irregular in the sense that they happen way too often but are pretty consistent about when they start. Anyways my period is now 5 days late and I havent had a single cramp/bloating/or any other sign my periods getting ready to start. I have had some weird pressure and major mood swings though. Could I be pregnant with the IUD/do the IUDs run out of hormone and become less effective? My husband and I dont use any other form of birth control other than the iud...