TMI but please help

I have a date tonight and i've had super bad diarrhea all day. It normally happens when i'm stressed so i'm used to it but its normally gone after 2-3 times of using the restroom. however, i've gone at least 7 times today. i took some pepto bismol about 2 hours ago and it hasn't helped at all and i gave been drinking a lot of water. this will be our 3rd date so it's not our first time hanging out but i'm definitely not comfortable saying "i'm stressed and on my period so i have super bad diarrhea" lol. we will also be at the drive in movies so it's not like i can just slip to the bathroom if it becomes a problem. he's coming to get me in like an hour. do y'all have any recommendations?