Period + white dress??

hey! so I'm in a bit of a situation. I'm supposed to start me period this Sunday, which isn't that big of a deal but I have an issue. There's a big dance I have that night, and in wearing a pretty tight, white dress. I'm generally fairly regular but sometimes it can come a day or two late or early. I checked this app and another and they both said it should be Sunday that I start, but I never know what time it'll start. I'm pretty good about not bleeding through anything if I'm careful (I wear both a tampon and a pad usually) but I'm just nervous about it, especially since my dress is tight fitting. Do you have any suggestions of what I should/could do? Anything is appreciated. Thank you!!