Clomid - please advice?

I have just taken my first course of Clomid due to not ovulating (presumably because of Depro). My day 21 blood test has shown I did not ovulate. Yesterday (day 26) I had the most vicious pains in my stomach I was completely doubled up for over an hour (they started whilst my partner and I were bd which was awful). When they ped it has left a very bruised feeling stomach. My GP says it is ovulation pains. Would this really happen so late in my cycle especially on Clomid which is supposed to make you ovulate at the correct time.