We have one and like many others have said: now he is here, and is such a gorgeous, lovable little boy, I am very glad he is in our life. I would say most of the time I reflect on how lucky I am that he is here, and more importantly healthy and happy, and I have no real regret. Maybe that would be different if he had been born with serious disabilities? A PPs point on this really struck me, as I don't think I did go into parenthood with an acceptance of what it could actually mean, if that were to happen. Maybe worth considering?
Even with a healthy happy baby it is relentless though. I had a very rough time with pnd and a non sleeping baby, and I often thought why oh why did I do this?! I now work full time too and feel like it is such a balancing act. If I let one tiny thing slip I think everything would come crashing down. I am far more serious about life, finances and planning for the future, as I want to do the right thing by him. I often think, why didn't I enjoy more the absolute peace of mind that I had in comparison before I was a parent? And save a lot more!
I also do feel inadequate a lot, like I do not really deserve him, he is so innocent and lovely. I think that just because you have a child you do not suddenly become a 'sorted' adult. I look at my parents 'failings' quite differently now. All in all a very odd mix of emotions! And a rambling answer to what is clearly a very difficult question!
You are very likely to love your child immeasurably and therefore not actually regret it, as once they are here you can't really look at it objectively. For us it came down to whether we could decide NOT to do it and move on happily without any nagging what ifs? The answer was no and so we took the plunge.
We now know what we know and given how utterly life changing it is, our decision is to stick with one, for many reasons, but mainly why rock the boat again and risk difficulties we cannot even imagine?
I think you sound a lot like I was, and honestly I can now definitely see that not having children is just as valid a decision, and could lead to a very happy and fulfilled life. If I were you I would try and see where you fit in the range of replies here.
Your partners view is also absolutely crucial, I would say if you are going into it with a plan to do a 50-50 split of parenting and household management then you have a good shot at being happy with your decision. If you are unsure AND your partner is also not convinced, it could lead to a lot of regret.
Good luck with your decision. For us, it really was not easy.