Depending on when the battery was changed last, try putting a fresh battery in and see if the problem goes away. If you use a chest strap, try cleaning the contact strips as those sometimes get dirty and don't read well. If neither of these solve the problem, who knows, maybe it is?? All I know is that I would be opposite - I normally register high with a HRM and my baby's HR is on the low end :laugh:

I have a Polar FT4 and have had this issue before. I am almost 8w5d, so there's no way it's picking up the baby's heartbeat, plus it happened beforehand anyway. I have always been able to fix it by making sure that the contacts on my chest strap were wet enough.

Other possibilities are that the batteries (either in the chest strap transmitter or in your receiver) are dying or that for some reason it's picking up someone else's reading. HRMs are generally made with enough code possibilities that your receiver will not pick up a reading from someone else's transmitter, but it's certainly possible. As someone else, said, too, the contacts may need to be cleaned.

oh thanks ladies. I bought my HRM this past February, maybe it is the battery. I do have a question, I have the polar FT4, how do I change the battery from the strap? It has this thing on the back that says "open/close" but when I try to turn it to open, it won't turn. Has anyone been successful with opening the battery cover on the strap?

edit** oh I also wanted to add, I always rinse my strap before putting it on, so I am sure it is wet enough.

If there's a slot running across the battery cover, try using a coin to turn it open; that's how I have to change my HRM.