Metformin

I just started metformin on Tuesday. Let me tell you so not fun!!!! I should have started my period Tuesday or Wednesday but it never came! I have taken test but all bpn. Has anyone ever started metformin and it delayed their period? I'm so confused because it's should regulate my period not make it late! And if it is shopping my period am I going to ovulate again ? Or an I going to just have to waste time waiting for af to show her ugly face?