6 week ultrasound..

I’m 6 weeks today and had my first ultrasound this morning. They only saw the yolk sac. My doctor said it was still to early to see a heart beat. I’m going back next week for a follow up ultrasound. Anyone else have this happen to them? With my first we had zero issues and everything went smoothly. Second time around not so much this is my rainbow 🌈 baby and I’m just so nervous now. 🙏🏻🙏🏻