Hello, i started with venlafaxine on january. my period was on the 6th and this month it hasn't arrived, i took a pregnancy test and came out negative?

Coincidence?: I'm not aware that Venlafaxine will cause missed periods. Generally a missed period or two is not necessarily concerning in itself. If you have no other symptoms you should see your doctor if you've missed your period 3 consecutive months (sooner if you have other symptoms). Of course, if you are having mood issues, this can sometimes affect your periods as well.