Missed period

Hello ya’ll im new at this, this would make this my first post... but im really freaking out.. soooo i just wanted to see if this might off happen to someone else..

heres my story...

I had the Nexplanon for almost 2 years decided to remove it because i had the worst headaches, so i did remove it on November, didn’t get a period while on it for all the time, i had my first period on January 12th after the removal, i was aspecting my p.. this month but it hasn’t come yet, i had brownish discharge a week ago and also today... im worry because i was sexually active although we did take precautions, im just wondering if this maybe signs of early pregnancy or just a sign the my p. Is about to come.. i took a pregnancy test came out negative also talked to my doctor about it she said it might be my body trying to figure out my cycle, since i was never quite regular, and now idk if its just me and my head i feel my dizzy also breast soreness but then i know this might be also my period coming! Has anyone had experience like this after removal of contraceptives?