Sooo worried 😥😥😥

Had my first ultrasound appointment today. My OB wouldn’t see me until i was 9 weeks. Ultrasound showed a strong heartbeat at 174bpm. The doctor said the baby was measuring smaller and I explained that my cycles were longer and ran around 34 days. He said he wants to see me back in 2 weeks for another ultrasound for measurement. He also said that the yolk sac was measuring slightly on the bigger side. When I asked him what that could cause he said it could cause chromosomal abnormalities and could cause a miscarriage. Anyone deal with this? He’s estimating I’m 7 weeks, 6 days.