For The 5 Months My Periods Have Been Regular As

For the 5 months my periods have been regular as clock work around 6-8th every month I say for the last 5 months cause i stopped takin the pill havin slipt from my bf. My last period was 8th Feb I hooked up with my ex on the 20th and took the morning after pill on the 22nd as I thought I ovulated and my period not long away was out of the fertile zone we hooked up again on the 26th and we never used anythin....on the 8th when my period was due I had what I only could describe as brown discharge to light that it barley covered a tampon and a towel was not needed only when I wiped it would show.it was very light with occasion seems jelly/tissue like and it only lasted 2-3 days top. I've had nothin since so was that my period???? Could I b pregnant????i took a test on the 8th and it was neg!!! I've normally get period symptoms but none this time I did have sore nipples but that went away my boobs so fill fuller and vainier but nothin else!!! Confused???