Ate, I totally get the worry, google can be so scary talaga! But honestly, kung wala siyang concern ang OB mo, that's actually reassuring because doctors know what they're looking for with placenta stuff, hindi kami. I have a few mum friends na nabasa nila din yan online and nag-stress lang sila for nothing, pero everything turned out fine. The best move is to ask your OB directly next visit, like "Doc, nakita ko yung grade 3 sa ultrasound, okay lang ba?", kasi kahit online research, siyang talaga ang expert na nakikita ang full picture ng pregnancy mo. Fingers crossed for you, mommy!