Since I've had quite a few bitches do this to me, I never jump into action the minute it drops any more, because I just know it's going to bounce around. I do check more frequently once it drops to see if it's the "real thing" or just a fake drop. lol Mine are pretty textbook once they actually (REALLY) drop - 99 for at least 4 hours. With that, it's pups within 24 hrs, and within 12 hrs once it goes to 98.
I've never had one go to 98 and come back up unless there was a problem (knock on wood, only once, a long time ago); usually it's the high 99's that they play around with.