Can you get pregnant if you haven't had your period for 4 months and are 51 years old and he's 56 years old?

A pregnancy this late is not unheard of, but not common either.

The mans age does not matter much at all, as we men are fertile often right until the moment we pass away at age 100 or even more.

It is likely that your now starting your menopause.

You could of course test for being pregnant.