I used to get this too. It used to just tick me off. My clock wasn’t ticking. In fact I don’t even like children, nor have I ever had any desire to have any. (People who have/like/want children - please do not be offended, it’s my choice to like them or not.)

Now that I’ve had a hysterectomy and “can’t have children”, people don’t say things like that anymore.

Of course, now I get the looks of pity.