Congrats on your pregnancy
I think the best thing to do is talk to your mental health specialist tomorrow. It is ok to take some anti depressants during pregnancy according to my GP. I spoke to him about it when we were thinking of trying for another baby. If I remember correctly he said that Prozac was safe but then you have the change over period and you could lapse when changing meds.
Its better to be a happy, stable mam on meds than the total opposite which is no good for anybody concerned.
Good luck tomorrow and hope you get the info you need.