Scared

I had my pee test at the ER and it came out negative , once I had blood work it stated 50% pregnancy , now they also did an ultrasound and nothing was seen . It worries me , in 3. Weeks I have another ultra sound and I am freaking out because it is my child if so , I hope they can see him or her . I also haven't had any bleeding or anything . Is that normal? I pray I don't have a miscarriage or anything like that . My husband and I have been trying 💔💔. We want this planned baby and I am super excited yet sad and scared over everything I read.