I say this all the time. As a matter of fact, I was just berated for saying this same thing last night to a derby league from whom I may now just walk away. If you want to be taken seriously, you CANNOT use "abbreviated" words, like "u," "ur," or "imma." Nor is it intelligent to use "there," "they're," and "their" incorrectly.
This is a pet peeve that will probably get me yelled at and accused of snobbery for the remainder of my life.