I started taking it around 7 weeks ago (I was on Celexa [generic: Citalopram], but it wasn't safe during pregnancy so my dr. switched me).
The first week I was on it, my pregnancy mood swings went crazy, I was breaking things and screaming, irritability shot up, I was restless all the time, and my anxiety went through the roof.
After about 6 days, those side effects went away. Now I just feel generally less irritable, but my anxiety is still around (Wellbutrin doesn't treat the anxiety the way the Celexa did).
By the way... you shouldn't base your own decision to take/not take a medicine on others' reactions and side effects of it. The only side effect I experienced with the Celexa was dry mouth, but a friend of mine had all the worst side effects, so she was switched. It's a matter of your physiology and the specific problems you're being treated for.