I am 25 and married.Am not on any birth contol and trying to conceive for 2 years.I have pregnancy symptoms (which I have never had)and was suppose to start my period on October 1st.It came 4 days early and was spotting on toilet paper only the 1st day,the 2nd day it was a little heavier... I used one pad,3rd day nothing,4th day brown discharge only on toilet paper.Could this have been implantation bleeding?

Please read this about implantation bleeding.

If you are still concerned take a pregnancy test in about a week.