Congratulations on your pregnancy!
I would talk with your Dr. who prescribes you the depression meds and your OBGYN about it. I'm not on them now but was on them with my DD who is 2 now and they both told me it was fine to stay on them. In fact, they told me it would be better for me to be on my meds verses off them and a complete mess. The meds were better then the stress would have been. Hope that helps!