Discharge

Can anyone tell me what kind of discharge this is? Also -

I have been having cycles of 31 days the past 2 months now. I am now on cycle day 21 and according to my app, I am 4dpo. I am 10 days before AF is due on 18th of March. Here is what has been happening -

First day of last period was 16th of February to the 22nd. But On the 28th of February I started having brown/pink discharge up until my expected ovulation day which was the 4th of March. It stopped until 2 nights ago I started having pink spotting that was only there when I wiped. Is this just ovulation spotting after ovulating? I woke up with a stuffy nose this morning and had sore heads the past few days. Also sensitive and bleeding gums. But today at cycle 21 am having cramping at both sides and middle? That comes and goes throughout the day. Can anyone help me.