Here's why and how to correct it:
* "Estas" should be "estás" (the informal "you" form of the verb "estar").
* "Haciendo ahorita" is a bit clunky. A more natural way to say "right now" is "ahora".
The correct and more natural way to say "What are you doing right now?" in Spanish is:
¿Qué estás haciendo ahora?