BBT has changed my dates!

Heather
Hi ladies,
My BBT is still elevated after ovulation, and seems to be on the up. I'm due my AF in 2 days and got a BFN this morning at 12 DPO. The elevated temps on my BBT has made Glow change my cycle dates, so it thinks I've ovulated once again.
My only symptoms, (which I'm not assuming mean that I'm pregnant) are constipation, a couple of hot flashes, a tiny bit of nausea and slightly sore boobs. 
Has anybody else experienced this?
Thank you in advance!