We have four, all twoish years apart, and a puppy, and still make jokes about twins, because when we were married my dh said 6 dcs and 2 dogs....
I love it, it was hard especially when the first 3 were under 4 together, as we had a major bereavement and some serious illness in my family. We also had to find a car that takes 6 and all the car seats plus luggage, and a house which was bigger and needed, and still needs a lot of work.
They are older now, oldest 13, they are great company for us and each other. It can be expensive, but I have learnt over the years what is worth spending on and what is not. I do put a lot of effort into cooking meals that stretch to 6.
But to answer your post, I never regretted it, except maybe on the winter school runs when dd was newborn, and I was struggling to get along the icy pavements with a double buggy and two little ones!
I think four was right for me, my broodiness is fading, and the puppy is my baby now 