Late - Need reassurance

Let me just say this before I forget but I have an IUD, and I've had it for 3 years in April which means I get it taken out in April. I am currently 23 days late for my period, but I am on cycle day 78. My last 3 cycles were 78,79,35. Could it be because of the IUD? Because my doctors were shocked that I even still got my period but would it stop it this close to being taken out? Or do you think it will show up within the next couple of days and I should just stop worrying about it? And should I contact my doctor?