Do opks get darker the closer you get to ovulation?

[Alicia870]

Wasn't sure if there's a pattern to it. This is the darkest line I've had yet and on cycle day 18 now - just wondered is this a sign I could be close to ovulation if line getting darker? Is that usually how it goes?

Definitely dtd tonight but yes mine always get stronger and stronger. Stay strong from any where between 1-4 days then drift off to nothing

The top one is earlier today and the bottom is tonight. Does it look positive or not yet? This is my first month using these and don't have regular cycles usually so not sure what to look for! Looks to me like the second line is darker?

You won't doubt it when it's positive. The second line will be much brighter and darker. You may still have a day or two to go. However, some women have lower LH and their opks never get fully dark. You'll have to go through the entire cycle to know.