OPK...

Hi! So thanks to anyone who reads this (:

I have never in my life used ovulation tests, however for a few reasons I have turned to using them now. I cannot predict where in my cycle I am because I haven't had one since I had my last child due to breastfeeding so that doesn't help. I'm curious as I don't want to spend a tonne wasting my money testing when I'm no where near ovulation, if you are no where near ovulation will you still get a faint line? Or if you have a faint line is it a good time to keep testing daily? I don't know if I'm making any sense but any help would be appreciated.

P.s I know it's not positive until the test line is as dark or darker than the control