When to go to hospital with 2nd

This will be baby #2. The hospital said to come when contractions are 15-30 mins apart because 2nd time is faster, but that still seems crazy early... With my last one they started at 8 mins apart and I labored like that for 14 hours before they got to 5 mins apart and I could go in. What are your docs telling you? Might be moot for me anyway as they want to induce at 37/38 wks as baby is less than 10th percentile but curious to know what your docs are saying.