54 DAYS!!!

So my cycles are typically 30-35 days. I started an antidepressant several months ago and i think it is messing up my cycle. my cycles have been getting longer and longer (40 days, 46 days). i am now on day 54. I don't believe I'm pregnant as I am having no symptoms and my husband and I have been using condoms minus one time just after my last period ended. We always start without a condom tho. what are the chances that I got pregnant by pre-cum AND I'm having zero pregnancy symptoms? I mentioned delayed menstruation last time I saw my psychiatrist and he kind of blew off the idea that the medicine could cause this. I'm not sure what my next step should be...should I just quit my med? talk to him about it again? see my GYN? I guess I'll take a pregnancy test in a few days if nothing happens. any advice?