I Found Out Almost 3 Weeks Ago That I'm Pregnant

I found out almost 3 weeks ago that I'm pregnant but I've been spotting and bleeding for the past 10 days. I've also had pressure along with aching in my lower stomach and back. I went to the ER and they said I had a UTI and my hcg level was 92.74. My last period was on Jan. 25 so I found out really soon I was pregnant. I should have started my period on Feb. 19 but started spotting the 17. I'm worried I might be having a miscarriage since I'm spotting and bleeding and with the aching I'm having. Do you have any ideas as to what might be going on?