So scared!

Today I went in for an ultrasound and they were able to see the gestational sac and the yolk sac but no baby☹️. I had a miscarriage may 4 which is ironically the same day I was suppose to have my period. According to my app I was suppose to ovulate somewhere between the 17th and 19th of may as well so I thought I would be somewhere around 6 weeks by now. I'm trying to stay positive but it's sooo hard. I went to the er a couple weeks ago because I had some cramping and they checked my levels which were only 16. I went two other times and they went up to 42 and then 154 and I haven't had them checked since then. I go back next week to see if the baby will be there and I'm so nervous they still won't see anything. Had anyone else had this same problem but had a good outcome, I definitely need some positive reassurance that everything will be ok?? 🙁