you can always adopt or freeze your eggs for later on down the road

well i have heard that it is the easiest to get pregnant at early age (25 and under)
after 25, it is getting a little harder and takes a little more hard work.
after 30 even more harder.
…

but thats what i heard over the years…

good luck

They will be reduced if you go through menopause in your 40’s. All that means is that you need to have your children before then. menopause is the time when you stop ovulating so until that point you can still get pregnant. You may need to work harder, try longer or even go on medications to help you ovulate more. I don’t know for sure, but it is a possibility. If you are ttc I’d go to the doctor and let him/her know about your family history and see if they have any concerns but I really don’t think it’s a problem, as long as you have the kids before you hit your 40s.
Good luck

edit: If your mom and grandma both had menopause in their 40’s you most likely won’t get it before then. So you still have at least 15 years to have another kid (if you are 25 now). 20 if you don’t hit menopause til mid-late 40’s