Help me find my clan :(

[Meggers]

I consider myself a pretty intelligent woman but I have a hard time wrapping my mind around exactly what a Scottish clan is and was. I have a few specific questions specific to my name (though I hope it helps other confused individuals) and I need a little organization with my facts.

I have one of the most common Scottish last names (Walker) and Ive had two different accounts of clans that I could very well be linked to. One of them is Clan MacGregor and the other is Clan MacMillan. Now, Walker is an English word but my family is not English. My Walkers are from Scotland--not England. Therefore, if I am not mistaken, our name was Anglicised from what it originally was in Scotland which I have learned, through just surfing the web, was MacNucator.

Neither "Walker" nor "MacNucator" are clans but both have been tied to other clans. MacNucator, Walker, and MacGregor share a clan crest and motto and I have been told by a MacGregor here on the boards that Walker was an alias used by the Gregors at one time. However, one cannot claim MacGregor ancestry unless one finds a MacGregor in their line? True? False? Im assuming true. I, personally, do not feel comfortable claiming clan ties if it's not certain. I like romanticising things sometimes, but I want this to be legitimate.

Today, I also found out from another wonderful member that the Walkers are a sept group of Clan MacMillan. I did some poking around on the MacMillan website and found that Walkers are pretty much openly embraced as a legitimate offshoot and would be welcomed into the clan just like anyone else bearing a sept name or even the MacMillan name as long as we register with the clan.

Now, is that even legitimate? How does one ever really find their clan if their last name is as common as mine? Can a last name like Walker really be tied to a clan at all since it's occupational? I have a hard time truly understanding how the clans work in the first place so researching this has been extra confusing for me.