Ok, so I have two possible days of O.....Did I O on CD15 or CD17? What do you think? If it's 15 as FF says and my temps point to, then I'm 12DPO and still testing negative

If it was CD17, then I'm only 10DPO and there's still a chance.....
Please let me know your honest opinion. Do you think I'm out? See, what happens is that since I'm on all these meds this cycle (and next too if we don't get our BFP) then my last Prometrium is Sunday night....so I fear that if I am pregnant and don't get my BFP by Monday morning then going off the progesterone will cause me to lose it.... If I do get my BFP then I am supposed to stay on the progesterone for 10 weeks.
Any advice or input you ladies might have is greatly appreciated!
Thanks!