I had my eldest at 17 & I have absolutely no regrets because looking back, I was such a mess at the time that it was the best thing that could have happened to me.
Don't quite know how I stepped up to the huge responsibility but I do know I could never have done it without my amazing family, & I am eternally grateful to my in-laws - they put us up til DH (who was 19 at the time) finished college & got a job & place of our own AND they always made sure he was doing his fair share of baby duties, because, being a teenage boy he wouldn't have gotten stuck in on his own. I know that if they hadn't pushed him to spend more time with our son I would have done it all myself because I felt guilty that he was the only one earning for the three of us. Plus all that practice came in handy when baby number two came along last year
Yes, ideally I'd have liked to have established a carreer before the whole marriage & kids but I honestly had no drive to do anything with my life until my son BECAME my drive . I know that it would have taken me at least a few years to get my act together if my little lifesaver hadn't come along.