period timing

So me and my boyfriends anniversary is in 5 days (September 10th) my glow app says I don't start till the 14 but sometimes I start ealryer than expected and my period seems to have a pattern of getting ealrier and ealrier every month. I really don't wanna start till after the 10th is there anyway I can like postpone my period? Sorry if this seems like a silly question I was just curious 😅