You need to contact a GA criminal defense lawyer or a GA public defender for the answer to that question. Please check this web site for a listing. Obviously you have a state and federal constitutional right to a speedy trial. What "speedy" is in the state of GA, legally speaking, I would not know. However, when the prosecutor knows that the case will be delayed due to a lab backup, one of the things he requests of you in open court (or your attorney) is for you to waive that right. Such a waiver (which is the giving up of a known right) often occurs among the many other things that defendants plead to when they are arraigned. You would have to check your file to see the status of this matter. Good luck.
------------------
Mark B. Replogle