It's scary when it goes off, I'm glad it was only a false alarm. I have one of these monitors. When DS was a few days old it started going off ALL the time. They ended up replacing the unit for us & it didn't go off for months. These days we still have the odd false alarm. Usually it's because the mats have slid & they're not completely flat, DH has fiddled with the sensitivity, DS is in a really deep sleep etc. I have had it go off right in front of me as I'm readying him for bed in his cot too, so I guess sometimes it just happens