Baby is tiny in the 5th percentile!

I am 29 weeks pregnant and I had an ultrasound today because my baby was measuring small. My husband and i thought the ultrasound went well until i received a phone call from a doctor saying that i need another ultrasound tomorrow because my baby is measuring in the 5th percentile. I also need to start going to appointments twice a week for a non-stress test (NST). I am so stressed out. Today i feel so out of it since i barely slept last night because i got food poisoning and ended up taking unisom and vitamin b6 to stop from throwing up. Has anyone else’s baby been in the 5th percentile? I’m worried about my baby girl and it just feels like too much.. 😩😫