No motivation

LJ • Baby girl born Feb 19, 2015 and second girl born Jan 20, 2017. Baby #3 due in October!
24 weeks postpartum and I have no motivation to do anything except take care of my little one. My house is a mess and most days I don't even get dressed or really even get out of bed unless she is awake and playing. Is it depression, hormones, or just plain laziness?  I don't know what to do.