rising temperatures

This may have been asked before :) but I couldn't find it when I did a quick search, so hope someone can help. I have a digital BBT thermometer which beeps after about 20 seconds but I've noticed that my temperature keeps climbing after the beeps, another 0.1, 0.15 degrees or more. Do I keep the initial temperature given at the beeps or wait until the temperature stops rising? :confused:

Normally your BBT thermometre should only 'beep' once a stable constant temp has been reached. For me, sometimes this is 30 seconds, sometimes is 3 mins - just depends. Sounds a bit strange that it beeps and then continues to change though. Maybe take it a couple of times, and get the average of the temp results