I haven't had a period since march 24 2012, I had a tubal 15 years ago, could I be pregnant?

It's possible, but not likely. Have you tried a pregnancy test? It could be that you just skipped a cycle, but try a pregnancy test. If negative, wait and see what happens for May when you would expect your period. If you don't get one for May, then see your doctor to determine a possible cause.