ttc / missed period

hey guys so im 21 days late for my period and idk why ive taken 4 hpt so far and it was about 2 weeks ago.(Negative) i experienced 2 days of brown spotting with no cramps yesterday and the day before now its gone can i be pregnant what should i do? FYI i used preseed before this cycle was supposed to come. im hoping im Pregnant but the negative keeps me wondering,sad and confused...