So, I'm in the middle of my first cycle (CD9 today), and yesterday I realized that the thermometer I was using must be inaccurate, since the readings it gives me are all over the place and also very low (ranging from 94.5 to 96.5). So I went out and bought a new thermometer (this new one is actually a Basal one, where the old one was not). I took my temperature with both and they definitely don't match up. The old, inaccurate one, says 95.5. The new one says 97.2. I'm pretty sure the new one is correct...

My question is, can I just start using the new one or will it totally mess up my chart? Or does it really not matter that it will mess it up since my old one is so inaccurate, my chart is already messed up? Any advice?