Oh, yeah, pregnancy is harder the older the body gets. I met my husband later in life--got married at the age of 30--and wanted children. Had my first and only when I was 32 years old--had high blood pressure through the entire pregnancy as well as pre-eclampsia (baby came 3 weeks early--after I was bedridden in the hospital for two weeks. And baby had some issues in the first six months of life, then had to cope with ear tubes, adenoids, tonsils...etc.). We had no trouble getting pregnant--it was almost right away--but we definitely had to be digilent about my care.
I have a friend who got married in her late 30s who wanted a baby, but they couldn't get pregnant. Tried for five or seven years. Then when they quit trying--they got pregnant. She had her baby when she was 41 years old. He is her only. Another friend of mine met her husband late in life and was pretty adamant about not wanting children. She either changed her mind--or they had an oops. She had her little girl when she was 38 years old.
There are pluses to having children when you're older, but I think you have a lot more stamina when you have your children in your twenties.
Unfortunately, not everyone meets their special someone during that period of their lives. The older you are when you meet someone and decide to have a family, the more realistic you need to be that you might have waited too long and you might not be able to have a child. All this talk about infertility help for older moms to have babies--there is now evidence that infertility help/intervention might not be all that great for the child.
Yes, I definitely think women have been sold a bill of goods that states don't worry, you can have children whenever you want. Um, no, actually, that's not true. And even if you are able to get pregnant when you're older, that doesn't mean you pregnancy is going to be without problems, or that the child won't have issues/problems. Career women who put off having children until later so they can have a career when they're younger should especially, seriously, ponder this issue.