Advice about worrying

I had a blighted ovum earlier this year in January. I am now 5 weeks pregnant with my second pregnancy. My doctor had me test my hcg levels and last Thursday they were 547. They couldn't test me 48 hours later with it being Saturday and labs being closed so they tested me Monday. On Monday I was at 3844. My nurse told me that's a very good sign and that if it was another BO that my levels wouldn't be doubling like they are. I feel like I just have a lot of anxiety being that my first ultrasound isn't for another 24 days (October 9th). Anyone have any tips on what to do to help keep my anxiety levels down?