Assuming that you are validly married, yes!
The fact that your bodies are no longer well disposed to fertility does not preclude you from having sex; think of Abraham and Sarah, they were clearly older and she was past child bearing years, and yet by God's grace they conceived — because they were having relations in later life. (Genesis 17-21) That is not to say that you can expect a miracle, but rather the fact is, had Abraham and Sarah not been having relations, that would not even have been possible; sex was part of their relationship even in their older age.
The same went for Zechariah and Elizabeth, who gave birth to John the Baptist. (Luke 1:5-23, 57-80) Age doesn't mean that sexual relations are not possible, it only requires that you are open to whatever miracles God performs in your life.
To use artificial birth control would be a sin, but the natural birth control of age is no sin, because God made us that way. We are working with nature, not against it.
So, Congratulations on your new marriage!