The labatalol should really start working when you take it. The issue at hand, the way I see it, is that you are at the end of a pregnancy that has already started becoming hypertensive. You have been having some PIH and readings are creeping up. You are so close to your due date and your body has probably had enough at this point. Do you have chronic hypertension? If so, this upward trend will probably continue. The good news is that you can take quite a high dose of labatalol - under your providers direction of course. And you are so close to your due date that you could have your section at any time if needed. Keep on logging your pressures and call them in. I would guess your provider would like to know your readings every day.
Good luck and let us know how you are doing.