Need answers so confused

OK my app says I was supposed to start five days ago and I haven’t started my period. It’s not blood, it’s brown and gooey that’s coming out of me rn and I’ve been having really bad cramps past five days as well. I am on the pill btw And I usually start my period when I get to my blue pills sometimes even white pills But I have three white pills left and then I start my new pack of birth control and I haven’t start my period yet or at least seen any blood yet. What could this mean?