Am I Pregnant? :: Brown Discharge, Tender Breast, Headaches

last week was my period week, but i had brown discharge throughout the week, with tender breast, my emotions were uncontrollable, headaches, backaches. could this be implantation bleeding? also, i bleed somewhat the following week on that monday but stopped. but the next day i woke up and have been barely bleeding throughout the day. i figured it was just my late period but its irregular compared to my usual periods. could i be pregnant? note: i still have sore breasts and everything. (very sore breast) and faint cramps.