Reddish Brown Discharge short period;

i got my period about a week early but it was very light lasted only 2-3 days usually it lasts about 5. and following about 5 days later on the day of my expected period i had a reddish brown discharge. it looked like i was about to get my period again but didn't. i've been constipated for about month now, headaches, frequent urination. very very moody. i'm scared i could be pregnant. the discharge stopped only a few days ago. My doctor wants me to wait and see if i get my next period in feb. then go in for a test. but im a young girl... and i cant have this on my head for another month. i took a EPT but i think i may have taken it early. and i havent changed my diet or anything. any advice? thank you