BBT raising after ovulation, didn't go back down this time

Usually my BBT raises after ovulation by about 0.6 degrees for 2 days then goes back down. It may bounce around a little, but it's low. This time it went up 2 days after ovulation and it hasn't gone back down 8 days later. Has anyone else had this happen? I have been feeling a little tired and icky so I thought I might be getting sick, but so far nothing. Waiting a couple more days to do a HPT.