Vegas...Alone?

It's my birthday tomorrow. We leave for Vegas on Thursday. "We consisting of my roomie, her boi, my sis, her boi, and me." The original plan was for me to take this dude I see but he messed up and his trip was terminated. Did I make the right move in going alone or am I the 5th wheel? Do you think I'll have more fun alone because I won't have to worry about someone constantly and what the want to do and if they are ok? It is my birthday and I'm going alone...What do you think?