Advice would be greatly appreciated !!

Needing advice ! I’m currently pregnant and just had bloodwork done yesterday. My doctor said my hcg was 7210 and progesterone 29 . I thought I was 7 weeks but she said it’s looking like more around 5 weeks and I only go for an ultrasound at the end of next week. I have a 9 month old and just recently stopped breastfeeding so I only got three cycles of my period the recent months but they are super irregular. Last month I had a chemical so I started spotting April 5 and got a heavier flow days later stopping the 15th. So I’m not sure if that has something to do with miscalculating how far along I am but I’m super nervous of a miscarriage. Before my daughter I had one chemical and one miscarriage at 91/2 weeks and right before this new pregnancy I had another chemical so I can’t help but overthink everything!