No confirmed ovulation

Frances

This is the first cycle since I started tracking bbt that I haven’t had a confirmed ovulation date. I always start taking OPKs on CD 10. This month, the first test I took was very positive, and then the next day it was negative so I stopped taking them for this cycle. Based on that and some symptoms I was having I think I may have ovulated on CD 11, but my chart is not showing that. Any ideas? Thanks!