How do I induce or delay my period?

I’m going to the beach next week and I’m supposed to start today but I haven’t.

I may start today but if I don’t idk what I’ll do.

Last month I was gone to the lake and I had my period while I was there but I was supposed to have it the week before and I wasn’t able to do anything.

I really don’t wanna have my period while I’m at the beach because I only wear pads and I won’t be able to get in the water.

So anyone know how I can induce it or delay it????

(also I’m not preg cause I’m not active)