The guilt of not having a kid — yet

Next month I turn 29. Unlike many of my friends who cringe at the thought of getting older, I'm surprisingly indifferent about the whole thing. And, no, I'm not just saying that because I'm secretly terrified of the fact that I'm entering the final year of my 20s.
 
In January I celebrated two years at Today's Parent, a job I thoroughly enjoy and learn from every day. And, as a result of my job, I'm confronted with the shadow of one particular "grown up" decision on a daily basis — motherhood.
 
Although I've always pictured myself as a mother, it was usually just a passing thought. Motherhood was always something I'd do "one day." Exactly when, I wasn't sure.
 
But in the last year or so I've become acutely aware of my feelings about motherhood. As much as I hate to admit it, I'm feeling that tick of the clock. I find that the minute you turn 30, people start expecting you to be expecting.
 
I don't feel particularly rushed. I've always been happy with my decisions and I have no problem waiting four or five more years before having my first child. But where I catch myself worrying is not about being an "older" mom — but making my parents wait for their first grandchild.
 
It's like some sort of bizarre, reverse "mommy guilt" — I feel "not-a-mom" guilt. Is that even a thing?
 
I consider myself lucky: I have two parents who raised my sister and I in a loving household. If I can be half as good a parent as my mom and dad have been to me, I'll consider my adventures in parenting a success.
 
My mom is naturally maternal: Her instinct is to hug you throughout the day and ask about the little details in your life, like what book you are reading or what friend you saw the other day. My dad is that playful father figure, always quick to joke and, even though he's well into his 50s, he still doesn't hesitate to get down on the ground to play-wrestle with his nine-year-old great-nephew.
 
When I witness these moments I feel guilty that I haven't given my parents a grandchild yet. I know they would never rush me or want me to go into such a huge decision blindly, but I still can't help that feeling.
 
In a time where women are starting their families later in life, there still seems to be that pressure to do it soon — tick tock, tick tock. And I want my parents to be young enough that they can still get down on the ground and play with my kid.
 
I can't deny those feelings of guilt, despite wanting to have kids later in life. And it's one of those frustrating situations where there is no solution — no right or wrong decision. I know I'm probably being silly, but there it is — always at the back of my mind.

But one thing I do know for certain: When I eventually do get to hold my own baby in my arms one day it will not only have the love of its mother, but two devoted grandparents who will love it to bits. It's going to be one lucky kid.

Did you start your families after the age of 30? Did you experience any "not-a-mom" guilt?