Need some positivity! 💚

I found out on March 30th that I was pregnant with my rainbow baby! I had irregular cycles due to PCOS. The last two times I bled were 4 days on February 21st and a heavier 2 days on March 9th. They went by the February 21st date and thought I was around 5w3d. Had my first ultrasound on 4/20 (should have measured 8w3d according to Feb. 21st date) and was only measuring 6w2d. There was a tiny little babe in there and heart rate was 115. They told me I’m due around Dec. 12th and that everything looked good since they can’t always see and pick up heartbeat that early. Just been super worried that something could be wrong since I have miscarried before in September 2014. I have another ultrasound for peace of mind on 4/28. Trying to stay calm and think good thoughts but could use a little positivity!