How do y’all BBT through a period if you temp vaginally?

Kat • Texas born and raised. 20yrs old and married to my soulmate. TTA

So, it’s my first month accurately tracking my temp (and hopefully last) and I’ve been doing it vaginally since I don’t trust myself not to mouth breathe at night. I was told you’re supposed to temp CD1 to the next CD1. Is there a reason to temp during your period? Can I just skip those days?