Please help

About 3 weeks ago, i thought i forgot to take 2 days worth of pills and i then took my sugar pill plus those 2 pills in one day, only to realize I hadn’t even missed any. The next two days i didnt take anything because i already took them by accident the previous day. Im wondering if this can cause breakthrough bleeding close to when my periods suppose to happen? Ive had brown discharge the past 2 days. I also had protected sex on december 17 but he didnt finish at all, and I have been really scared to get pregnant because of my mishap with my pills. Someone help me out and ease my mind!