My DD is Beth, just Beth.
I constantly get people saying, "what a lovely name, is it short for Bethany/Elizabeth etc?" and even one idiot FIL who insists on calling her Bethany (a name I hate).

She still has a nickname- "Bug" - long story.

But I'm with Feathertop, give your child the name you want them to have, either way you will still get people assuming to call them something else, long or short!