Feeling low

Feeling low during pregnancy. 4 weeks away from birth. I do not recall ever feeling depressed until I got pregnant. Did anyone feel depressed during pregnancy and then feel normal after baby was born? Everyone keeps telling me to be prepared for postpartum depression since I'm so upset now but I feel like a lot of my anxiety is stemming from how I feel physically. Super tired and sick all the time. I'm hoping when my body feels somewhat normal again so will my mind. Let me know your personal experiences :)