No there is no way to make it shorter. Just take any needed supplies and go to the ladies room when you need to.
Is there a way to make my period shorter I am going on a field trip in a few days and I am still going to be on my period then. It will be the last day of it. Any natural ways that won't cost me money?
Sorry - there is no way to make your period shorter; if there was such an idea, it would be promoted all over the place. Who wouldn't want to shorten their period? So, just bring supplies and it will be all good. Have fun on your field trip.