HELP. First Ultrasound tomorrow. Dying from the nerves

I'm so nervous right now. I will be 6 weeks, 6 days tomorrow and we have our first ultrasound. I'm so paranoid that we are going to get in the doctor's office tomorrow and see nothing, an ectopic, or a molar pregnancy. My HCG at 5 weeks 5 days was 20,485, and while the nurse told us thats "beautiful", I still can't help but worry. I've had on and off cramping since my bfp, and no spotting since a brief show of faint pink on tissue for 5 minutes around 16dpo. Finally starting a to get the queasiness, and have felt like my boobs were going to fall off since my bfp I as well.Theoretically, I know things should be fine, but I can't help but think to myself about how low the odds were for us to conceive. If we were so lucky to hit those low odds, could be as unlucky to hit the odds of losing our sticky bean?