The pill

So I’m a little worried but I’m not sure if I need to be, I’ve been on the pill for about 9 months now. Since starting I’ve been taking it every single day at the same time and I’ve never missed one, my boyfriend and I don’t use condoms because they irritate me, so we solely rely on the pill. I finish up the active pills on a Friday, and start the placebo week on a Saturday and by the following Tuesday my period starts every single time without a doubt.

However this month, yesterday(Saturday) I took my placebo pill and today (Sunday), it’s like my period has begun? Should I be worried??