How should I wear short hair for a wedding?

My boyfriend's brother is getting married and he wants me to come with him. My problem is my hair. I have a short choppy bob (think Rhianna in her video Umbrella) with a shorter bang. On a regular basis, I straighten it and throw some wax in it to give it a bit of spikey-ness. I have no clue how to wear it for a wedding. My hair is just about brushing my shoulders and has a bunch of layers and parts on the left side (naturally). I'm wearing a A-line cream-colored tail dress that has a floral print on it. Please help