I bought this item after getting an all-clear 9 week scan. I wasn't sure whether it would work yet as I was so early (was 9+1) and in fact the first couple of days I only picked up my own heart beat! But on the third day, I drank loads of water, waited until my bladder was really full (it was quite painful to press on, and made me feel a little bit nauseous, to be honest) and moved across my belly really slowly... BINGO, there was baby, little heart beating away! :OD
After having four miscarriages (one late), this item has really put my mind at rest. I will only use it every few days (as I don't want to scare myself or baby!) but knowing that I can listen to little bean for the next few months has relieved some of the anxiety I have been feeling. Once baby starts moving, I probably won't use it as much, but I would definitely recommend this product to anyone in the early stages who is anxious. It is great to hear your little one BUT please dont stress if you can't hear it. It took a lot of practice and a lot of patience, and I had to limit myself to only listening once a day, for no more than 15 mins. Otherwise I would have gone mad! The gel you get with the product is good, but I found that baby oil also works very well ;O)
So, to sum up:
1) make sure you have a very full bladder if you are earlier than 12 weeks
2) make sure you have used plenty of oil / gel
3) dont use it for too long at one time and try to use it no more than a few times a week ;o)
4) listen to your own heartbeat to compare (yours beats about once a second and is on both sides of your lower stomach area, above your thighs) - and keep the volume at half until you find baby or you will deafen yourself!
5) work very slowly across your belly, starting just above your (ahem) 'hairline' and pause every cm or so, to allow the 'echo' to come back
6) DO NOT STRESS if you can't find it first time (or second, or third!) Sometimes baby has its back to you, so you wont hear it until baby turns round. My little one is obviously stubborn, like me!
Hope that helps, and happy listening!