Could celexa or wellbutrin (bupropion) cause my period to be extra long i'm normally 3 days and its been over a week. i'm on bc also should i worry its miscarriag?

Possibly: There have been studies that have implicated several antidepressants in changing the characteristics of the menstrual cycle for women including bupropion and escitalopram.In addition to venlafaxine you may benefit from checking out http://www.Ncbi.Nlm.Nih.Gov/pubmed/1899086 and http://www.Ncbi.Nlm.Nih.Gov/pubmed/12013367.

Yes & no: Yes, Celexa (citalopram) can sometimes causes changes to your menstrual cycle (http://www.Drugs.Com/sfx/celexa-side-effects.Html). Changes have also been noted w/wellbutrin (bupropion): http://www.Drugs.Com/sfx/wellbutrin-side-effects.Html. If you're reliably using birth control, shouldn't need to worry about pregnancy, much less miscarriage, but regular use is key.