CAN SOMEONE EXPLAIN WHATS GOING ON TO ME

My last period was November 26,2018 my average cycle days is 31 In December I was supposed to get my cycle December 27,2018 at least that was what this app said buht in other words I didn't get a period I figured it was due to stress and weight gain because of Thanksgivings and Christmas was so close together and I ate like a cow so January 22,2019 night I had pink discharge throughout the day and stop with a worst headache and running nose the exact same thing happened the next day to except I seen a little blood, then on the 24 at the end of the day which was around 12 the discharge was brown with the same headache Im confused and don't understand what is going on