The older I get the harder it seems.

It seems like the older I get the harder it is to have kids.i mean I am only 29. I had no problem getting pregnant before and I know others would love to be in the boat I am who don't have any kids at all but I have always wanted a big family and it just seems like I just can't get pregnant. My last son it took me a year and this one 6 months. Just frustrating. Anyone else like that?