35 weeks measuring 30 weeks

I went into the doctors the other day to find out I was measuring 30 cm I had been that for the last 4 weeks. She sent me in for an ultrasound to find out my daughter is in the 8.2 percentile for amniotic fluid and the 11% for her over all growth. They worry at the 10th percentile I guess. She has not grown anything in 4 weeks. She is also breech and they were going to try a trial of labor but are planning a repeat c section. She is weighing approximately 3 lb 11 oz. How soon should I expect to be going into labor? My water broke with my first daughter at 34 weeks 6 days. Now I am 35 and 1 day this pregnancy