During the follicular phase, if we have a sawtooth pattern with temperature spikes, we know we need to nourish our Yin/ Estrogen. If our temperature doesn't spike quickly or enough mid-cycle, we know we may need to boost energy or clear through blockages so that ovulation can occur, or warm our womb in our luteal phase to support implantation.
We can learn so much more from tracking our BBT than from an OPK, so it's always our recommendation.