I have been on Effexor XR (75 mg) for about a month and a half. Last month, after I had been taking it for about 3 weeks, I started experiencing light spotting in the middle of my cycle. I have been taking Yasmin for birth control for almost a year now and have had very regular periods and have never experienced spotting or irregular bleeding while on it. I called my gynecologist and she said that she thought my body was adjusting to the new med. After about a week of the light spotting, the bleeding became heavier and eventually became as heavy as my period. This lasted for about a week and then I got to the week of nonactive pills in my Yasmin pack. The period continued through those pills, so it lasted two weeks. Since then I have started taking Wellbutrin as well because the Effexor alone was making me have mood swings. The combo has worked extremely well in treating my social anxiety disorder and depression. However, yesterday (about 2 weeks after my last period ended) I started bleeding again. Today I had mild cramps and I feel like my period is starting--9 days before I will start the week of nonactive birth control pills. So it seems that I am having another 2-week period. Could this be caused by the Effexor xr?