BBT was below normal... now normal. What?

Has anyone ever heard of or had below normal bbt (96.2 - 96.8 range) that adjusted to normal range (97.3 - 97.6) on its own? Started seeing an acupuncturist in January. Always has below normal bbt, but never diagnosed with thyroid problems. After this last cycle, my temperatures started increasing and have leveled out to normal bbt ranges. Tested for pregnancy and definitely not pregnant. Just curious if anyone has ever experienced something similar.