Regular periods but not ovulating

After all the test we have found out that even though I'm very regular I don't ovulate. Is anyone else in this predicament? I'm always 25-26 day cycle, my cramping during AF isn't bad, I don't bleed top heav or light... last cycle my follicles were 15.5CM the same day I ovulated so I'm guessing my eggs don't mature enough???? Anyone?