I'm one of the few people in the UK not on Facebook : D You're very welcome to send me. Private Message (PM) on here, but if you're worried about anything in particular you shoukd check with your midwife or consultant.
I know how stressful the early part of pregnancy is - well, all of it actually!
If you're looking for general info about the fetal heartbeat, there's some help here:
http://www.buzzle.com/articles/normal-fetal-heart-rate-chart.html
The heart rate can vary eg if baby is sleeping or moving it can slow down or speed up. If you're listening yourself remember that there are other sounds in the womb eg the rush of blood through the placenta, which can be mistaken for the fetal heartbeat. I watched some videos online to see how to find it and they gave me an idea of what it should sound like. But again, if in doubt, check with a medical professional.