Repeating last two to three typed letters/characters

I've'v been having trouble lately with my Mac book pro and typing. It's repeating the last three letters/characters I typed (see first typed word), particularly when I'm typing fast. It seems to happen whenever I start a new window. Like a document or an email. (This is me trying to figure out the issue with stream of consciousness: Here ere is an example of me typing in my email. Why is this happening? is it just the first word that I type into an email? -- Let'set's try this again. Okay, so it is the first set of letters typed into a window. ) I went to system preferences and changed the repeat letter option to off, so that shouldn't be the problem. Nothing in particular happened before that could be the cause, like a spill or something, and since it's groups of characters I feel like it's not because my keys are sticking. Should I take it into the Genius Bar?