Back in the sixties I watch a movie very similar to "The Omega Man", but I thought Sidney Poitier was in it and that he and a white women were the only two left. Ring any bells to anyone?

The Omega Man starred Charleton Heston. He finds a black woman and white boy. The Omega Man (1971) (http://www.imdb.com/title/tt0067525/)

Here is Sidney Poitier's filmography. Sidney Poitier (http://www.imdb.com/name/nm0001627/)

I believe the movie you are referring to was called, "The World, the Flesh and the Devil",

Classic Film Guide (http://www.classicfilmguide.com/index.php?s=essays&item=66)

Hope this help.

How about "The World, the Flesh and the Devil"? 1959 with Harry Belafonte and Inger Stevens.