clicking hips

Titus has me scared that something is really wrong. Three times in the last 24 hours I've heard his hips clicking. I already know that he has severe hip dysplasia. He takes 1000mg glucosamine and Chondriotin a day. And we go for small walks daily. Our vet says that he has to stay active or it's going to get worse fast. I'm careful to keep his weight in check. So how concerned should I be about this clicking? When I've heard it he doesn't seem to be in any pain. Which doesn't mean anything I guess, he could just have a high threshold. I knew as soon as we got the news about the ruptured fatty pad in his knee, the hip dysplasia and the arthitis that he'd need corrective surgery eventually. I think I'm just panicking since I hoped the need for surgery would be a year or two out.