Opk questions

Amy
So I have never taken an opk before but I thought I should since this is the first cycle we are trying to conceive after a tubal reversal. I've been charting everything but I don't think I ovulated when the calendar says I did. I didn't have any of the cramps or discharge or sore books ect like normal so I took one of those tests today and it's lighter then the control line but does that mean the window is closed for this cycle or maybe it hasn't happened yet?