Hi Amber!
I think you should go ahead and get a new thermometer. They're cheap and it will put an end to your doubt. As for normal daytime temps, I agree with Andrea - it varies from person to person (I had to go online to convert to Celsius to understand your post - LOL!
If the problem is not your thermometer, you could be having a longer than usual follicular phase, which doesn't necessarily mean there's anything wrong. Could be caused by stress, lack of sleep, extreme changes in diet or exercise.
There is a bright side: if you didn't temp, you'd start thinking you were late and keep breaking your heart with BFN's.
Hope you solve this mystery and, if you haven't O'd, I hope you do soon (a later O is just as good, so keep up the BD and FX!)
Ana