I am having light brownish dishcharge since yesterday its doesn't have odor or anything

also i have been having these times where i get really warm suddenly
and feel like i can't cool down, i am typical cold all time, my breasts have been pretty tender i have been feeling nausous the past 2 days and i have had some slight cramping

I had sex for the first time 8 days ago on oct 28 now

i am on seasonal birhtcontrol where you only have a period every 3 months and i have been on it for 7 weeks

I was wondering if there is any reason for this if its because i am new sexualy active or if its an infection?

If you have any idea please help