Are swallow tattoos just for Military?

I was thinking of horseshoe tattoo with a swallow flying through, but I don't want to look dumb since I was medically discharged from navy basic, and I know that thats a popular one with sailors and other servicemen. But I also want something that represents that chapter in my life and means good luck as if to mean so i don't spend any more time in the hospital. Any other ideas would be cool too.