I always thought I would have 2 kids. DH convinced me to have the 3rd and why not 
Well...... I regret it now...... I got PPD after the baby was born and got mostly over it but occasionally the thought comes to my mind that things would have been better if we had stopped at 2 
She's lovely and my easiest baby!! She's not the problem. The problem is everything else...... she was born in different circumstances to her siblings.
We had to move in into inlaws house. And it's not easy.............. but that's subject for a different post.
These thoughts creep onto me..... eldest is having some trouble at school: I would have more time and clearer head without a baby. Middle child is acting up: would have been easier without the baby, I would have more time. We've been trying to look for a house: we could do with 2 bedrooms if we didn't have the 3rd one. We may move country: would be easier without the 3rd one, especially the travelling. We may need to consider home schooling: .........
Does it ever get better?
is it just the baby stage that is more difficult?.... They're age gap is not much, 4 years between eldest and youngest, so soon they'll all be at roughly similar stages?