Tracking my cycle

So I took an ovulation test today for the first time. The chart in the instructions says if I have a 28 day cycle, then I should start taking them on the 11th day; which is tomorrow. My predicted ovulation day is the 9th of May. So I was wondering, if there’s even a faint line, does that mean you’re going to ovulate soon and then as you get closer, it gets darker? The pamphlet didn’t really say a lot. I got a pack of 10 from Walmart so I have 9 more to take. I’m obviously not trying for another baby right now, I’m just curious about my cycle. But I also have to say I feel kind of crampy😂 just on the left side.