Contractions???

Ladies so I am on my 3rd baby and I am 31 weeks exactly as of today, but my first one was born at 33 weeks and ended up via csection my contractions were nothing but back pain. My second I had voa scheduled csection no labor pains. But I keep getting sharp pains in my belly and have a dull lower back ache the belly pains started about a few hrs ago I havent started timing them cause they arent lasting very long at least not sharp pains