I think you are just freaking yourself out. I would not put any faith into a longer ring finger. just because you aren't 100percent into your relationships with your guys may just mean they are the wrong guys for you, not that you are a lesbian. it doesn't mean you have to grab the first lesbian that comes along to test out your theory. but by all means, if nature takes it course, and you find yourself attracted to a girl somewhere down the road, explore the relationship.