Just heard baby's heartbeat for the first time!

I bought a fetal doppler from Ebay a few weeks ago, but unfortunately I misread the listing which said it can detect baby's heartbeat from around 20 weeks onwards

So I sold it on Ebay and bought a more sensitive one which arrived this morning. It's supposed to be able to detect the HB from about 10 weeks +. I tried it out this morning but heard nothing. So just tried it again... I heard my baby!!!! Such an amazing sound!!!