+ Opk and small follicles?

Hello. I had a internal ultrasound last Wednesday to check the size of my follicles (Cd11. I was on my first round of letrozole 2.5mg cd 3-7). My Dr didn't give me any numbers, just quickly relaid some information to the tech and then simply said to me "well you are on a low dose and it's still early, come back Monday and we will check again, then if need be I will put you on a higher dose"

So I go tomorrow for another scan. This afternoon I recieved a strong positive opk on CD 16 (which I've never really had as I struggle to ovulate on my own)

So my question is this, is it possible to ovulate and conceive when follicles were small on cd 11?

Can you have a +opk and not actually ovulate?

Could this be promising for this cycle or no?

Thanks!