Ovulation help?

wy

I am in an interesting situation and this is my first time TTC so I’m not that knowledgeable on ovulation yet. I use the clearblue advance and it’s always been low, but yesterday morning it finally showed PEAK! I took another this morning and it was still peak, but when I took it this afternoon it was low, like barely there. I bd and was wondering if I am in my fertile windows or if I just missed it?