Scared I may not actually be pregnant!!

I went to the women’s clinic here to confirm my pregnancy via urinalysis which came out positive. Based on my last period I should be 6 weeks and 3 days. I went in for my first dr visit and when it came to the ultrasound he couldn’t find anything. He did eventually find a sac but it was so tiny. He said that either I’m not as far along as we thought or there is no baby. He sent me for the usual blood work when you first get pregnant and added an hcg screening to it and then I go back in 48 hours for another blood test to see if the hcg levels are rising. But I got a little worried and decided to take a regular pee test (if my hcg levels are rising the test should appear darker than the first) but the test came out 100% negative! Not even a faint line. Wtf 😭 I’m so terrified that this may be a chemical pregnancy. Has this happened to anyone who had a positive outcome?? I don’t think I can wait a week to find out the results!