When my twins were born one was real sick and she needed blood but when the blood was drawn the nurse said I wasn't a match how is that so

It can still be a fact that you or that your wife can neither one be a match for her. My blood type isn't the same as my mother and fathers. A good reference comes to my mind. Have you ever seen the movie, "My Sisters Keeper"

Get a DNA test.

Way to deep to try and explain blood types ( a entire chapter in high school science) but the child gets blood type form both parents and may not be exact the same as either.

A DNA test would prove parents.

A DNA test is the only sure fire way to see if the twins are really yours. There is no other way short of being there when they were conceived that is.