I am childfree by choice and now in my 60's. I don't regret my decision at all and never have.
I will be honest. I do sometimes worry that if I live to be very old and DH dies before me I will have no one to care about me. I have a very small family and do not live very close to them.
I am a real worrier though so I may well still worry if I had children. Of course children can fall out with you (DH has had no contact with any of his family for years), they could emigrate or, of course, they could die before you. My neighbour is 95. She had 4 children but they are all dead.
When we got married I was 25 and DH was 23. I thought I would probably have children just because it was the done thing but DH was adamant that he didn't want any. That was mainly due to his awful childhood.
Anyway we talked at great length about it, weighing up all the arguments and eventually decided it was not for us. We both felt that the planet was already overpopulated so no need for us to add to it. Also if I had had children I would have wanted to be a stay at home mum but we could not have afforded that as I earned far more than my DH. They were not the only reasons but the main ones.
I have had a lot of rude comments made to me over the years, some by people I hardly knew. Told I was not normal, asked why I got married if I didn't want children, told I would be lonely when old etc etc. Thought that was all over but I now I get asked a lot if I have grandchildren and when I say no that often starts the questions of why I don't have children.
I know quite a few childfree woman, all of them married. I have 4 cousins and 2 of them are childfree. My brother in law has 3 sisters and 2 brothers (we all meet up as a family fairly often) and none of them have children. I also have 3 nieces and nephew and 2 nieces definitely don't want children.
As I say, I don't regret not having children and neither does my DH. When our nieces and nephew were young we enjoyed having them to stay with us and even taking them away (just us and them) but it was wonderful giving them back! I would though far rather regret not having children than regret having them. Sadly I know quite a few woman and men that do have children and regret it