Pregnancy can cause a lot of mood swings and make u think u feel things u dont. I dont think your doctor would put u on medicine mid pregnancy unless he/she felt u were really beyond hormonal and a danger to urself. Would you be able to and want to talk to a councillor? You always can vent and talk here but someone that is right there and a professional might help more. I cried a lot in my second trimester this pregnancy and still do from time to time. I spend entire sessions with my councillor crying, but no one ever has mentioned medicine to me. It just helps me to cry and talk it out. Maybe that could help you feel better too.
Depression is a terrible thing but you need to talk to your doc. Its no joke, my dad committed suicide about 8 years ago. Better to be diagnosed and treated then do something like that. And it may not actually be depression it may just be hormones, but talk to your doc and have your baby checked. Better safe then sorry.