Ay, aking dear, naiintindihan ko ang takot mo, pero ito talaga ay kailangan mong pag-usapan ng maigi with your OB agad, okay? Single umbilical artery ay something na kailangan ng regular monitoring from your doctor, hindi lang online advice.
A few of us moms here have had similar findings, at honestly, ang best reassurance is hearing directly from your doctor kung ano ang next steps para sa baby mo. Please don't stress alone, set up an appointment kaagad if you haven't already, and ask your OB lahat ng questions mo. That's what they're there for, ha. Sending you strength, mama. You're doing the right thing by being attentive.