Then where the heck did those dragons came from. I thought it was somewhere in the Silmarillion saying that he created them i dunno for sure though could be wrong?
Glaurung, the first of the fire drakes was known among other names as the Father of Dragons and the Worm of Morgoth. He was raised from young by Morgoth, and it is easy to come away from the Silmarillion with the impression that Morgoth created the Dragons. Nowhere in the Silmarillion does it actually say that Morgoth created the dragons, however. In places it does mention things like Ancalagon being the first of his winged dragons etc, but again I dispute Morgoth is responsible for their creation.
What I am getting at is the difference between creation and selective breeding. Without a doubt Morgoth was responsible for the appearence in Middle Earth of certain breeds of dragons. He would have done this, however, by a slow process of selective breeding rather than a process of creation. To better understand this, look at farmers or dog breeders who manage to breed an entirely new breed of cattle or dog. Okay they have created something never seen before, but they have bred these animals, not created them.
So, Morgoth could not create life himself, but by whatever foul means he used, he could breed new species from old ones. We can see this with his "creation" of orcs from elves, and again possibly with Trolls from Ents. So the question, as you mentioned, really is, "where the heck did dragons come from?"
JEA Tyler suggests in her Complete Tolkien Companion...
It is possible that the race of Dragon-kind was not originally evil but lured into evil ways by Morgoth the Enemy far back in the Elder Days, though other theories say they were in fact demonic powers of the same order as the Balrogs, Maiar in the service of the self-styled Lord of Middle Earth.
Personally I favour this view of Dragons being Maian spirits too. The Maiar took many shapes and forms, and their powers varied greatly from one to another. At the will of Manwe, Maian spirits became the Giant Eagles, while at Yavanna's bidding, other Maian spirits became Ents. In a similar way, I believe, some of the followers of Melkor could have become Dragons.
I am of this opinion mainly because the dragons are very intelligent. They are obviously "thinking" beings as opposed to the beasts Yavanna was capable of creating (Yavanna being able to create life, but like the rest of the Valar, banned from creating "thinking" races.)
Failing this, the only alternative I can see, is that Yavanna or one of the other Valar created some prototype Cold Drake species of beast, which Melkor then managed to change as he had the Orcs. After thousands of years of selective breeding, he may finally have managed to breed something that had evolved into the intellegent fire drakes of Glaurung's kin.
Perhaps the truth is somewhere between these two theories, and the intellegent dragons were perhaps Maian spirits that inhabited the bodies of dragon beasts that Melkor had bred for the purpose.