Light spotting 6 days after sex

My boyfriend and I had sex on the 12th day of my cycle. 6 days after I spotted red and pink with barely there cramps for 2 1/2 days. Not even enough for a pad and only when I would go to the bathroom. It stopped and now today a week later and 2 weeks from the day we had intercourse Im spotting very light pink again. Ive been very light headed to the point of almost fainting a couple times and my breasts are s ore(But they normally are this time of the month anyways) Im ALWAYS regular and have NEVER spotted in between cycles. Im not due to start again until Sunday the 30th. Ive taken an embarrassing number of pregnancy tests and all have been negative but I am only 2 weeks from the day of conception if I am indeed pregnant so its kinda silly for me to even be testing yet but cant help it. Hoping Ill be one of the few that is lucky to get an early positive I guess haha. Has anyone else had this and been preggers? Im going to try really hard to wait until Sunday or Monday and test again... Any info or others experiance is greatly appreciated!!!
abby