HELP!!!! BBT contradicts my OPK

I feel confident I ovulated on 5/29 early in the morning. I work night shift so I'm awake at 1am and I had extreme cramps especially on my right side that lasted about an hour or so. On the 28th I got a positive opk and on the 27th my ClearBlue tested peak day and I had EWCM BOTH 27 and 28. Anyway, I'm confused because my temp has not greatly increased. It's hard for me to test at the same time every day because I work night shift. How much stock should I put in my bbt? I was feeling so confident until my temps didn't rise like I thought they should. Help!​