Tdap Vaccine

I'm in college and I am due for my Tdap, which I need to be up to date for or I can't attend clinical. I'm in the first trimester now (12 weeks), but I know you usually dont get it until your third trimester. Can you get it twice? Or am I just going to have to wait until my third trimester? I'm asking my doctor about this next week at my appointment. But I have to let my school know about my immunization status.