Periods post IVF

So my ivf was unsuccessful, I started spotting and then had to stop my progesterone suppositories in order for the flow to continue on it's own, had my period in August and now in Sept this is supposed to be my first natural period but it's already 3 days late from my average cycle before starting IVF. Has this happened with anyone that the period gets delayed? I have zero pregnancy symptoms as we had unprotected sex in my fertile days. I am getting that cramps period like feeling in my stomach few times a day but no sign of a period.