a) Side effects reported in premarketing Phase 3 trials have included 1) menorrhagia/ metrorrhagia
(basically means Irregular menstruation
) as well as 2) breast pain
, so possibilities are their it may be due to EFFEXOR (venlafaxin-Is a serotonin -norepinephrine reuptake inhibitor
works at brain level).
b)Stress can also cause irregular menses.
c)Their are some other issues that can do that (like THYROID PROBLEMS), - some blood test needed to be done in order to diagnose the cause.
PLEASE SEE YOUR PHYSICIAN AND LET HIM KNOW Whats going on.