Prozac, Wellbutrin and Xanax while TTC & Pregnancy

I've been on Prozac, Wellbutrin and occasional Xanax for years now for bad depression, and tend to be very sensitive to it (a single missed dose is keenly felt within 24hrs), so I'm really nervous about my meds, and possibly having to stop them once pregnant. The idea of stopping, then going into a downward depression spiral really scares me.

Anyone have any experience, either with pregnancy and the listed meds, and/or taking/stop taking psych meds while pregnant? Thanks!