Is not wanting kids normal?

I am about to hit my 35th birthday and still find myself single and not really had a “serious” committed relationship. By serious relationship I’ve never lived with a partner and built a life with one special person so the usual marriage settle down and start a family which seems to be the norm for most people.

I would probably put myself in a box called serial casual dater. I usually have a boyfriend or sometimes two but I’ve always kept them separate from my space where my financial independence, career and living in my own flat is more important than sharing it. But as my mid point of my 30s approaches I keep thinking that if I don’t have a kid soon it might never happen. And I’m ok with that but it would seem my sister and my parents think otherwise.

Surely I’m not alone in my readiness to never be a parent? Is this fine? Should I feel bad about not making my parents a grandchild? Should I feel bad that I don’t feel the need to invest in things to leave to the next generation because I just spend all my salary on myself?