BBT rise before OPK?

First time temping. CD 15 temp I think was high because I have a cold and had terrible mouth breathing and a bad night sleep. When I discard that temp it still shows O day as CD14. I’ve never gotten a “surge” that early which is how I typically tracked for O. I had a feeling in the past that I would O before my opk would turn positive because of my CM. Is this even possible? Do you think my chart is wrong? Maybe the cold is making my bbt a little higher. Based on cramping and CM turning dry, I suspect O was CD16, which put a damper on my trying because I usually don’t O until 18-21. 🙁