My SO is a Lazy Slob (Rant/Kinda Long)

My SO will not help do household chores! I'm beyond frustrated.  He and I both work full time jobs, but I'm the only  one who keeps the house up including grocery shopping, laundry, and cooking. I'm a FTM due in October and I'm concerned about the increase in household chores that will come once baby arrives. I don't know how to get him to pull his weight around the house; I know I'll really need the help when the baby is here.  I've asked him repeatedly (almost to the point I fear of being a nag); I've outright called him a slob; and, I've told him I'm his partner, not his damn maid. I'm at my wits end! What to do before it gets worse?