Escalating basal temperature???

My basal temperature is usually somewhere in the "low" 97 degrees area... Well after I ovulated it's just been in the 98 degrees area. I wake up and check my temperature at the same time every morning everyday. With the exceptional of a couple days here there depending on if I have to get up earlier for work. But normally I check at 0630. The past week I've been watching to see if it goes back down and it hasn't. Today it was at its highest. Is this a bad thing?? Can anyone explain why this is happening????