It doesn't matter. I dropped with all 3 of my children around 30-31 weeks. I delivered my first at 35 weeks (medically necessary induction), my second at 40 weeks, 4 days & my third at 38, weeks 3 days.
My son was breech, but he turned and dropped the night before my water broke and he was born. My daughter on the other hand dropped about 2 weeks before I had her. Both were natural labors with non medical interventions to start/speed/progress labor or dull the pain. First was 10 days early second was 5 days early.