When are we supposed to get the T-Dap?

I'll be 39 weeks on Monday and still haven't had my T-Dap shot. I keep meaning to ask my doctor, but a few weeks ago I asked the MA as she was taking my blood and she said I'll get it at the hospital. When I told my husband this (he's a pharmacy technician), he said his pharmacist told him that I should be getting it while I'm pregnant, not after the baby is born. I'll ask my doctor on Tuesday when I see him but I'm really confused. When are we supposed to get it?