I have seen the word "la" in a sentence., and it doesnt look like an article. Example - someone asks me over the phone, 'kote ou ye la?"

"la" could be a definte article as in: liv la - the book.
"la" could also mean  "here" as in chita la. - sit here.

But in this particular instance, "la" stands for 'right now', 'at this time', or 'in this moment'.
Not to be confused with the Haitian Creole word "kounye a (now)".  It does not replace "kounye a".
It is a manner of speaking, an expression, or an intonation used mainly when asking questions in Creole.

If you are learning Creole, this is one of the words you will learn to use by habitually listening to Haitian people speak.

Example:
where are you now?
kote ou ye la?

What are you doing right now?
Kisa wap fè la?

What do you have at this time? 
Kisa ou genyen la?

What are you cooking?
Ki manje wap fè la?

What book are you reading now?
Ki liv wap li la?

Why are you crying now?
Poukisa wap kriye la?