I had one when I was 18 years old, in a newish relationship. It was an agonizing choice, but definitely the right one for me. It did haunt me, for years, and most especially because that newish relationship turned out to be a 17 year marriage. Each time I was pregnant with what became our three (very wanted) children, I irrationally feared that something would go wrong because of the choice we’d made many years before.
However, having an abortion at 18 enabled me to have a life far different from my mother’s, who had me at 19. A much better life. A long, stable marriage. Enough time, money, energy and love to be a better mother to the three kids I had nearly 10 years later. The ability to choose my destiny. It also afforded my (eventual) children to have a much better
childhood than the one I had.
So, yes, it affected me in a negative way, but I’m completely certain that the positives still outweigh the negatives, in my situation.