Babies Heartbeat on the Monitor

Basically just wondering if anyone else has experienced this and it be normal or ok. We had an ultrasound yesterday and baby is definitely head down...like she had trouble getting a measurement. So way down there. lol Anyway I've been admitted into the hospital due to preeclampsia so we're on the monitor constantly. The thing is they have only been able to pick up a loud strong heart beat right below my left rib cage. Just wondering if any of you have experienced anything similar??