Pill and period

How long did it take you to get your period once you started taking the pill, I started taking it at the beginning of last week and my period was due the next day I haven't gotten it even though I was on the red pills my period is now 8 days late, I've been getting cramps like I have my period, I'm starting to get scared thinking I might be pregnant because my boobs have gotten bigger but I'm not sure if that is a side affect of the pill