I'm level 28 on my second playthrought, the first playthorught i wasn't enjoying my character then i started another character, anyway, this is my second playthorught and i never saw an Elder Dragon, in my both playthroughts i never saw any..

I can't imagine how people say that the game is getting boring because they need to kill a Dragon in every 5 mins, i mean, really ? I never saw an Elder Dragon, how can you have killed so many of them if i never saw one, lol.

Depends on how you play. I have only seen one.

Get to a higher level. Ancient Dragons make Elder ones look like babies.

Woah, there is Ancient Dragons ? Nice !

level 50 is the soft skill cap
if you're not there yet I don't think you have any reason to worry
at least I hope so cuz I'm around that level and I haven't seen any yet either, just blood dragons and the basic and named dragons

I have seen many elders and others. I'm level 57.

According to wiki it's possible to encounter them after lvl 23 but they are pretty rare at that level.

I am level 42, encountered 2 elder dragons so far. One outside Riften and one outside Winterhold. I think they start appearing at level 40 or so, because I never encountered one before that.

I was doing College of Winterhold quests and it seemed like an elder dragon attacked every time I set foot outside. The dragon skeletons kept disappearing though, so I thought the dragon was coming back to life or something. That is until I went into town and found out the mages were just cleaning the courtyard by using Winterhold as a garbage dump. The jarl's building was covered in dragon skeletons.