DO YOU THINK IM PREGNANT??

So my last period was last thursday ( August 17,2017) my boyfriend (of a year and 6 months) and i have had sex every night since then, (usually we do rough sex) and last night (August 24, 2017) i went pee and when i wiped, it was light pink. I put on a panty liner and i would pee every hour to see if i was still wiping up pink but it just kept fading as the hours went by and after 4 hours the pink was gone. I never cramped, my boobs arent sore and i didnt have any pregnancy symptoms BUT im still really scared and tonight i got lightheaded and nausea for about a hour and that was it. Could i have just been spotting because of having sex too much? Can i REALLY be pregnant? Or Can it be stress? ( Ive been having lots of arguing with my parents and on top of that, my moms family made us loose our home so we're living with family now and ive been really annoyed and depressed for the past 5 months).

Note: i took a pregnancy test today and it came out as NEGATIVE!! Did i test too soon?!

Also i had sex almost every night BEFORE my period came on.

PLEASE HELP!! I DONT KNOW WHATS WRONG WITH MY BODY!!