When I was pg with DD I bought one from eBay (and the gel) - knowing that I may not always find the hb, and the stress that may add.

Anyways, at 13 wks I managed to find the HB from DD, and same with DS. I didn't bother trying to use it any earlier than that as I knew I probably wouldn't be able to find the hb. This time around I have detected a hb from about 11 wks. And yep, it is definately reassuring .