New thermometer question..

So apparently I have been temping with the wrong kind of thermometer. Just a plain Jane oral thermometer. This a.m. I tempted and charted. I posted earlier about this, bc my temp this a.m. made my FF chart to be completely out of sync with GLOW chart. I went to the store this a.m. and purchased an actual basal thermometer. I know that by starting it tomorrow, it will throw my temp off from where it has been on my charts. My question is, should I waituntil my next cycle day 1 of AF to start temping with the Basal? Or can I just start tomorrow morning?