FF has given me open circles on my chart... I'm assuming it's because my temps are higher than usual during AF...not really sure why that is. I've been waking a lot between 4-5:45 am, but that should only make my temps lower, not higher! Does anyone know how long the batteries usually last in a BD thermometer? I've only used mine for about 2 mo's, so I wouldn't think the batteries were dying already! Any of you girls had this problem with your thermometers? Thanks... I think FF is messing with me already! This better not be a sign of things to come.... Grr!