yep, I was the same way, started trying around 16 weeks and I heard whooshing sounds but that is all I ever ended up hearing through the whole pregnancy. not worth the money :(
Guess I got screwed. Lol I read the reviews before I bought it and they all said it sucked, but I bought it anyway like the dummy I am. :(
Sorry to say but I have it and the thing is a piece of crap. I can here just as much now at 37weeks as I could at 15weeks...its the whooshing and thuds but never a distinct heartbeat at all. Lots of gurgling and tummy noises etc but nothing else...huge waste if money!!