Pregnancy Depression

Can you have this type of depression while pregnant or is there a certain medical term they use for it? I’m pregnant and my pregnancy has gotten me so depressed. Also people say I should be worried about this depression because it might be a warning sign for after birth, but it seems like the only thing that makes me happy about my pregnancy is my child itself. Like feeling a baby kick, or shopping for him, or thinking about my future with him. Any help?