Normal?

I went for my first ultrasound when I was estimating myself at 6w5d and all they saw was a sac, no heartbeat and no fetal pole and baby was measuring 6w exactly. They suggested a repeat ultrasound in 2 weeks. So, that was last Friday. I just got the results today. I have a small subchorionic bleed (but I haven’t had any spotting), and baby was only measuring 7w3d when I should have been almost 9 weeks along. We did get to see the heart flickering, and the heart rate was 157, which they said was within normal ranges. Has anyone else experienced this and had a healthy pregnancy? Am I worrying over nothing? This is my 2nd pregnancy, the 1st one resulted in a missed miscarriage so I’m a little on edge about everything.