BBT charting. Oral vs vaginal. Tips on the latter. Your thoughts/experiences?

[Lillypilly]

In the past I've charted orally, but results were erratic (I have a chronic illness which can affect my temps, and mostly anovulatory cycles) so I gave it up.

My FS now wants me to chart vaginally.

I feel like such a dill, but I am having great difficulty with this - it takes me multiple attempts to even get a temperature reading. I feel like there's no point charting vaginally if it takes so long, surely it can't be accurate. Who knows what my temp does in the meanwhile?!

Can anyone who has charted vaginally give me any ideas on what I may be doing wrong? It's not the thermometer, it's definitely the user!

And overall, does oral vs vaginal temping make that much difference so long as you're consistent? I understand the mouth-breathing concept possibly leading to inaccuracies, but I'm not a mouth breather. I think I should switch back to oral testing.

Would really appreciate other people's thoughts on this one. Thanks, lovely people.