I've been charting my temps for 2 months and have begun to see a pattern, however my BBT thermometer is a total pain in the butt! It takes about 7 minutes before it beeps. I got it at CVS and originally thought it was broken as they are generally supposed to give a reading after 1 minute, so I returned it and they gave me a new one. However, this new one is taking just as long. Where did you guys get your BBT thermometers -- and how long do they generally take to give a reading?