Antidepressants...quit them cold turkey?

Is it bad to completely stop taking them? When I found out I was pregnant a week ago, I stopped taking my antidepressants entirely. I'm guessing I'm about 6 weeks along, Dr appt isn't for another 2 weeks... I'm already starting to feel depressed, like non stop crying spells and easily raged over stupid little things. Can't tell if it's hormones or my body going through withdrawls from no medication. I've been taking wellbutrin/bupropion 300mg per day for almost 4 years... anyone else know have any experience with this? Obviously I'm going to do whatever the doctor thinks is best for me and the baby, but wondering if the community has any input.