Hcg rising after told I had a miscarriage by ER

Okay so a week ago Tuesday found out I was pregnant Wednesday light spotting happened went to er said cervix is still closed but hcg was only 10.9 Thursday had ultrasound didn’t see anything so was told I’m having a miscarriage. A week later on Tuesday got 2nd hcg draw went down to 10.6. Today on Thursday hcg went up to 16.2 which they said I went in too early so wasn’t exactly 48hours which they think is a good rise. and have to go in again next week. I don’t understand what is going on can I possibly not be having a miscarriage? I still have light red spotting no cramping anymore haven’t passed any clots or tissue. I also had a uti and was dehydrated they said the uti could be why I was spotting. I don’t want to get my hopes up but has anyone ever had slow rising hcg and they had a successful pregnancy? I just want to know if the baby will be okay or get the miscarriage over with so I can try again this has been such a hard time dealing with this.