I sure did! It can predict a miscarriage...it got me through that tough first trimester. I temped until 11wks...you have to stop at that point (12wks) because the placenta takes over and your temps go back to pre-ovulation levels.
Since these were our rainbow twins and you have double the cramps, a few spots here and there are normal-temping SAVED me in first tri when it was too early to be scanned, etc.