30+5 and baby is measuring 34+4

I just had an ultrasound today and my not so little girl is measuring almost 4 weeks ahead of schedule!! I haven't been diagnosed as gestational diabetic but Dr says I'm borderline. Has anyone else had this happen and what was the outcome? She is my 2nd baby, my son was born last April so they will be 15 months apart when she arrives in July. I'm due 7/30 but now wondering of they might induce and I'm terrified of a c-section, I don't want one at all even if she is measuring big!