I really wanted to get one due to the amount of complications and scans I've had this pregnancy, also contractions and still the odd spot of bleeding.

The reason I haven't is because there are no long term studies done on the effect of daily use of them so I've read...I know the companies selling them on ebay recommend use only up to twice a day for that reason.

I'd really love one though, but I was concerned that it would be like getting a small u/s everytime i used it. Apparantly it uses sound waves to measure the HB.
What do others think about this? I'd really love one for peace of mind, but I don't want to stress about using it either.