BBT = basal body temperature. That means the temperature that your body is before your metabolism kicks in and gets going. Therefore it MUST be the first thing you do, the minute you open your eyes or the temperature won't be accurate. You should also take it at the same time, even if it means setting the alarm at a ridiculous time so that you can do it accurately each day. And it should be done after 3 hours solid sleep and preferably under the same conditions each day. Things like an extra blanket, more clothing, air conditioning, mouth breathing etc can all affect it.

I found it much easier to temp vaginally. The alarm would go off at 4.30am. I'd pop the thermometer in, wait for the beep and then put it on the bedside table and go back to sleep. When I woke up I'd check the temp, clean the thermometer and then enter the reading on FF. Once you get into routine it is easy and your body will wake without the alarm after a while.

Of course, the downside is when you get your BFP and your body STILL wakes you at temp time even though it doesn't need too.

Lisa