Day vacay on my period!?

I'm going to NYC for the day(4 hour bus ride there) and I'll be on my period. I'm extremely upset that I'll be on it because it's a lot of walking and I'm worried about bleeding through! I'm very small so I HATE tampons I avoid them as much as possible but when I do wear them I have to wear the small ones. Any advice on how to stay fresh while I'm traveling and walking around a lot? I know the small tampoks won't last long. Especially on a 4 hours bus ride....