Bbt restarting and period

Hi there,

I'm thinking of coming back to bbt - it was the one thing that I think helped me get pregnant when I did. However, now we go sleep so I got worried about waking up my son. The other thing is.. I always did it vaginally for more accurate results- I just stated my period and Glow suggests bbt.. what are your suggestions? How do you all do it? Thank you xx