BBT question

Hey just a question 
​They say your bbt should be between 36.2 (97.2) to 36.5 (97.7). 
Mines way lower started at 35.80 (96.44) then dropped to 35.35 (95.63)
​Then peak next day to 35.80 (96.44) 
​I got my smiley face on clear blue.. 
​My temp last few days is sitting at 35.40 (95.72) 
​Sorry from Australia we don't do Fahrenheit we do Celsius. 
​Does you bbt need to be at a level to convice??