Should I keep being positive or is this what happens before AF?

So here's my chart.. My temps kept climbing and then went down the last two days so I figured AF would be here today or soon but now they have spiked from 97.88 yesterday to 98.31 today (no factors should affect it - been doing the exact same way at exact same time every morning, no meds or alcohol etc).. I'm wondering if I'm still in or have u girls seen this kinda thing before AF? And sorry to those who suggest testing but I got a negative 12dpo and afraid to try again until I'm late by a week and I'm 16dpo today.