ovulation confirmed? help!

Fallon
Question for any ladies that know anything about charting & BBT-
I've been charting with the app OvaGraph and it indicated a temperature shift indicating ovulation on CD 17 and my temperatures after the shift have all been higher but not above my cover line. My question is..do your temps post Ovulation have to be above your cover line to confirm it? 
I'm so confused and TTC number #2. 
Thank you for any help!