First month on metformin and a late period

Kassey
My periods have always been pretty regular but my doctor decided to start me on Metformin(I don't have PCOS) to help promote my ovulation. I am currently 4 days late, few symptoms. Just wondering if this is normal or such? Waiting Y test for sanity reasons but I think I'll break down and test and either way the results are; I'm calling my doctors office.