Pain in ovary

Ok so according to this app my fertile week was last week. Thursday was my highest percentage day and my husband and I had sex that night and the Saturday after. Usually during my fertile week which is my ovulation week I will feel just a little bit of pain in my ovaries. Last week i didn't feel any pain at all. Yesterday I noticed light cramping and today my left ovary was hurting. It wasn't severe pain but pain I usually feel each month. I'm confused by the pain. Did I ovulate today or could it be implantation? Any thoughts?