That way you have time to grieve and also it helps date the next pregnancy. I had a m/
c in December and we fell pregnant again in March
after waiting one
cycle. About 5-6 weeks along we had another m/c. Now in hindsight I wish we would have been patient and waited a little longer for my body to heal properly. I have never reacked my BBT, but have heard that you start tracking on the first day of your period. Make sure to track daily and to take your temperature first thing when you wake up.