If you're at all unsure, don't do it.
It's one of the biggest commitments you'll ever make and because it affects another person so hugely, it isn't one to be taken lightly.
There are lots of parents who are unsure, go for it and love it. There are also lots of parents who are unsure, go for it, and hate it. Once the genie is out of the bottle you can't stuff it back in. The latter is rarely discussed because it's such a taboo, but plenty of people feel that way, I promise you that.
Having a child is so, so hard, in my opinion you have to really actually want it in order to do a good job and see it through.
I wanted it soooo much, went for it, and utterly adore it. Never been happier. But I fully recognise that it's not for everyone and it's like a bomb going off in your life, everything changes and you can't undo it!
The 'what if I regret not having them?' is a common feeling but not reason alone to have them, when you could equally regret having them. Ask yourself honestly: is that feeling coming from deep within you, because you really want to be a parent and have a child? Or is it the result of living in a society that pressures all women to become mothers, points out the ticking clock, acts like not having kids is a failure, prizes motherhood and suggests that women without kids are less than?