Blood Dragons were kind of easy even at the start. You probably met an elder dragon by now and just didn't know it. It's one of those dragons that keep circling in the sky without attacking anybody. If you can get a hit on it then they will behave like normal ones and start attacking you and villages in the future.
Oh you must have done a bit of the main quest then. I took my time with the main quest so I only saw them when I was level 20-ish. Took a lot of tries to actually hit it and the first encounter was a bit scarry xD
This looks so worth getting. Might invest in a copy of it today for ye olde ps3.
Keen on fighting dragons and other macho shit like that to massage my manly ego.