How old is too old

Im 47 never bore children before. But then again never tried .we went to a fertility doctor who told me I have a zero chance of getting pregnant naturally .lol .since then been pregnant twice both ending in m/c very active .beat cancer and now ready husband is 37 lol .. my husbands grandma bore his mom at 50 ! .sometimes I feel selfish for wanting a child at this age .. .