No it really isn't.
My dgm - babies every 2 years from 22 to 44, obviously before the pill.
My dm, babies at 28, 30, 34, 38, 42, 44
Me, baby at 45 on one tube and half an ovary
Dsis1 - babies at 28, 34, 41
Dsis2 - babies at 24, 26, 41, 43
Dsis3, baby at 41
Dsis4, babies at 37, 39
Maternal cousins are the same.
@zov You may be from a family with short lived fertility but my family doesn't have any issue conceiving in our late 30s and 40s. For us it is normal. Most of us can get pregnant sitting on a warm cushion and it isn't funny, so we all double up on contraception, and don't stop taking it until periods have stopped for a year.