Late, but been on birth control for years

So last month, my period came in earlier than usual (before I started my placebo pills). It was light, but it got me confused as to why it started so early. It also lasted for about 8-9 days when I usually go about 5-6 days. I’m supposed to start my period three days ago according to the app, but I haven’t yet. I’ve always taken my birth control religiously, but I feel like something is not right with this. I’m getting anxiety into thinking that I’m pregnant, which is silly since I’m on birth control and I haven’t started my placebo week yet. What is going on here???? HELP!!!!