I'm On Effexor And One .5 Klonopin, I Have Been

I'm on Effexor and one .5 klonopin, I have been on these medications for more than 3 months (klonopin over a year). However, beside the normal side effects i.e. dizziness, tiredness, stomach issues including more reflux and occasional diarrhea I am now experiencing an delayed period, I took a pregnancy test and it was negative. I've never had issues with my cycle or my yearly pap. Could this delay be related to the Effexor?