Getting pregnant after having a premie

Hey all! My partner and I have an almost 2yr old son and were TTC starting in December. But I am nervous. My pregnancy with our son was totally normal but then all of the sudden at 35 weeks I went into premature labor- noah was breech, a footling, and I had a bulging bag. It was SCARY. It was an emergency c-section and he had complications afterwards, but he's okay now! Anyways my question is- my doctors told me that since I had my first child as a premie to figure any future children will be a minimum of 4 weeks early- has this happened to anyone else? I'm looking for feedback from moms with more than 2 child who've had kids after having a premie. Did you delivery esrly ?