I need some reassurance

M

When to the ER on January 19th I was about 8 weeks pregnant my levels were 108,.10, then I went back at 11 weeks pregnant and it went to 54,510.0. My OB said it was normal. My babies heart beat was 164 BPM then went to 154 BPM. Should I be worried. Do babies heart rates do that? Baby was moving and everything. I am a first time mom and I had a miscarriage in August so I am just cautious. ☹️ I am 13 weeks today.