I first heard my baby on my SIL's doppler at 10 weeks (but she's a midwife and very clever at finding heartbeats, LOL). I think you're right, it is a lovely thing to look forward to for your appointments. Not sure if its such a good thing if you're worried about your baby... if it were me, I'd be listening out for it *all the time* instead of relaxing and looking after myself... I'd probably get a bit obsessive about it and be intensely stressed if I couldn't find it (like if baby kept moving out of the way or something).