Hi mama! Don't worry too much, a lot of us have had this happen at 21 weeks, and honestly marami ring nag-resolve on their own by 32 weeks, so there's still plenty of time para tumaas ang placenta mo. The best thing is just follow your OB's advice, stay hydrated, avoid heavy lifting, at make sure you're resting well, some of my mum friends swear na ang consistent prenatal check-ups at good nutrition talaga ang nakatulong. Since you don't have specific restrictions from your OB yet, just live normally but take it easy, at mark your calendar for that 32-week scan kasi doon na talaga makikita kung ano na ang status. Fingers crossed for you mama!