What is the difference between pansexual, bisexual, and omnisexual? How do I know which one I am?

All I know is that I love anyone (with a preference for women) regardless of gender. I would say gender does matter to me since I prefer women, but I would love anyone regardless, and would gladly date women, men, and everyone in-between. not only this, but if my love transitioned, I would still love them.