When i had a scan at 8 wks 2 days the babies heart beat was 174 bpm. So maybe you could just not be as far along as you thought.
Maybe you ovulated late and are not as far along as you thought. When I was 6w the heartbeat was around 120 so maybe you just closer to the 6w mark than 8weeks like you thought. I'm sorry you have to go through all this stress. All you can do now is treat the UTI and try to take it easy. Feel better.
Keep us posted as to what happens.
Okay, sometimes it will let me show a web address but sometimes it won't. I will PM you the website for HCG levels.
http://www.*****************.org/duringpregnancy/hcglevels.html
I wish I could be of more help with the heartrate, but I don't know for sure exactly what it should be. I do know there is a wide range depending on how active a baby is on any given day. Just do what the doc says and stay off your feet no matter what.
Above I have given a website address for HCG levels in pregnancy and those sound fine and are fine according to that website.
If anyone else on here has info on the heartbeat, that's great, but if not, I would google it and see if you can get any info. that way. I would do it myself, but I am getting ready to leave for the day from work.
Please keep us posted and I will keep you and your little one in my prayers. Please, please try not to put yourself under too much stress. I know it is easier said than done, but it's not good for you or your little one.
Take care and again, let us know what happens and how you are doing.