Period

Hello ladies, I have a question. Have been doing some research but still no answer... I am on my third day taking my placebo pill of my birth control. My period hasn't quite come yet but I can see a brown smudge color when I clean myself after peeing. I wanted to know if stopping the "inactive" pill would it stop it from coming and just continue with an active pill instead & although there's a sign it might be soon.. I honestly don't want it to come due to having a sweet 16 for my sister this weekend and didn't want to have to worry about this:/ if you guys can help me or advice me would be really nice 🙂