Early Period

Hey everyone. My last pill in my pack was Sunday night and I started my period Sunday day. I didn’t take my last birth control pill that night since I started and it lasted my normal 5 days. My period normally starts on Tuesday/Wednesday. It was just the slightest bit lighter in flow but lasted the normal 5 days. I also normally will have some periods that’s are heavier and some that are lighter. Any explanation for why it would have started early?

I had been taking my pills normally. I have been a bit stressed lately. I was also on a camping trip when it started. I don’t know if stress and being out in the wilderness for 3 days had anything to do with it lol but that’s the only other things I can think would have affected me.