Can post partum depression happen during pregnancy?

This is my 4th pregnancy, hopefully this will be my 3rd live birth. I'm 37 weeks pregnant. This one was a complete surprise, due to failed birth control. We didn't find out till it was too late terminate (as bad as that sounds please don't judge or leave mean comments). I just can't seem to be excited for the baby I'm just more excited to not be pregnant. I'm more so dreading the fact of having another baby and the responsibility of not 2 but 3 kids. The idea of 3 kids just seems too much to handle. I've tried to act like I'm excited hoping it will change my mood and it just isn't working. My husband has been as helpful as he can but he works 3rd shift 12hr days. Between sleeping eating and driving to and from work we don't see him often and won't see him on more regular schedule till late January when the busy season slows down. I'm a stay at home mom. My parents and grandparents have all passed and his parents believe that they struggled so "it a right of passage" and we should struggle too. So all of it is always on me.

I've never had post partum depression before, but this is the first time I don't have my husband here on a regular schedule to lean on and mentally I'm struggling....can I experience ppd while pregnant or is there another name for it since it's not technically post partum yet...?