Promising chart?

I think I O’d CD12 but also had another weird dip on CD 14 so not totally sure... but I’m also wondering if this is what they talk about being a triphasic chart? Although the last two days I dropped .2 in temp.. if it keeps dropping am I out for the month probably? Or is it normal to have a slight drop?

On a side note the nights have been increasingly colder the last two nights and my husband insists on sleeping with the window open and fan on.... maybe this is causing the drop?

Thanks!!