Knee cap tendon pain. Help?

[Goku5lp]

I can feel a vertical line on my knee cap and it hurts only when I sprint or workout it out a lot. When You straight out your legs you can feel the tendon that connects your kneecap to your thigh right? Well mine feels like there is a hole or seperation on the layer that goes over the kneecap. I'm thinking it can be my tendon that is torn but how if my leg doesn't feel weaker or nothing it just hurts. Unless its slightly torn. It sometimes twitches after workouts or does a weird movement if I flex it to fast.