I've had this great basal thermometer for a couple years now and the battery low thingy keeps beeping at me so I know I need a new one. Thing is I can't find any anymore. The one I have now I got a Target but when I've looked over the last month or so I can't find any but your standard kind. So then I check CVS and I can't find any there either. So where are you guys getting your basal thermometers these days?