Help!

Ericka
I have the absolute WORST periods. It started tonight...a week early. I'm traveling to Las Vegas Thursday - the 3rd day and usually the worst day of my period. It's the day I barely make it to work...there's no way I'll make it 6 hours on a plane. How can I possibly fly without being a total mess??? 
I would cancel, but it's my sister's birthday. 
Any suggestions are welcomed and very much appreciated.