Mama, ang spotting in late pregnancy can mean different things, kaya please go to your OB or nearest hospital right away para ma-check properly, hindi ito dapat i-diagnose online, lalo na may abdominal pain ka. Better to be safe, especially at 34 weeks pa lang.
One of my mum friends had something similar at 35 weeks at okay lang naman, pero importante talaga na ma-assess ng doctor immediately whether kailangan mo ng emergency care. Don't wait, mama, go now. Keeping my fingers crossed for you!