First, I will say that everyone is different on this. But the one common thing is feeling a cramping or pulling or slight pain on one side of your abdomen.
For me, they are pretty intense because I have PCOS and I also get them pretty much all cycle. But they are the most intense at O time. I get the pain on one side and they last anywhere from 5 mins to hours. Sometimes, they also radiate into my hip or lower back.
But really, if you have the cramping on one side around O time, then i would say it's safe to assume it's ovulation pain. But like I said, how you'll feel it or for how long is all completely unique to you. Some women don't even feel anything at all!