BBT question…

Sadie

Hi everyone I’m new to tracking bbt so I’m not super familiar with all the rules. But I have a question some of you may be able to help me with… say I wake up with my 18month old or my 3 year old at 4 am but I get up to tend to them then I go back to sleep around 4:30 then wake back up and check bbt at 5:30 or 6:00

Would it be very accurate? Or should I not count that reading as accurate?