Single umbilical artery

I had my 20 week ultrasound. I'm glad I snuck it in a week sooner than I was supposed to because they discovered the 2 vessel cord. My Dr is concerned that I'm measuring 2 weeks behind. She didn't leave me feeling very ... idk optimistic? She just said sorry that you expect good news at the ultrasound and sorry for the bad news. I was left with nothing besides we need to see what the cause is. Baby looked fine... just small.

I got impatient waiting for the perintologist so I called after waiting 2 days (Dr wanted me to be seen within a week). My appointment is next Tuesday. I'll have another ultrasound and hopefully I get answers. I feel like I had to rely on Google for answers which is never good. Baby feels strong. I get kicks pretty constant. It puts my mind at ease a bit. I'm just trying to relax until I know more. It isn't always easy. I think the concern is growth restriction not that she said that. I'm trying to boost protein intake to help as much as I can.

Has anyone else gone through this?