Brown spotting on the pill instead of period

Last Monday was supposed to be the day I get my period, always comes on a Monday or Tuesday every 3 weeks! I am on the pill and I’ve been on it for about 2-3 years now. My lower back was hurting, that shooting pain up ur butt lol, and some mild cramps and bloated was. I had all my period symptoms, but no period, no red heavy blood flowing, ONLY dark brown discharge. And it’s like dry when I wipe myself, and barely covers a pad. What does this mean? Could I be pregnant? I had unprotected sex this month but I never missed a pill. I always have red heavy flow, but this time it’s just dark brown spotting. Then that Wednesday, 2 days later I took my pill again and started a new pack, it went away Like it would usually do for my period when I start a new pack. Is this normal on the pill? Should I test or nah