Hi Tatyana. This is maybe not my place to speak but it is very possible in USA. I can't speak for anywhere else as I do not know. It is very very common, although typically with men in mid 30s and up. Not to say there is a certain age, but it's just more likely.

I myself have no biological kids, but I dated a woman in 2008 for just 2 months but to this day, he comes to stay with me 3 weekends a month. I love this boy, my boy. He was 2 years and 9 months old when I met him...he will be 12 in June this year. It is so very possible, I promise. Here's a couple pictures of my little guy.