Bbt confusion

Kim • TTC #3 since March. Have a baby girl born March 2013. Baby boy born March 2016.
Normally my temps start high and then dip before AF comes. This month my temps have been all over and I'm very confused. School is out now so I'm not waking up at the same time anymore. Yesterday yesterday at 10 dpo and bfn. AF can come any day now so I'm confused why my temp raised. Any opinions would be helpful, thanks!