Do you think I'm Pregnant?

I need a bit of advice as I'm not quite sure if I am or not.

My boyfriend and I have been having unprotected sex for the last 2 months. I use emergency contraception as my mode of birth control because I was waiting for my insurance to clear my coverage for an IUD/birth control.

My period is late by a week, I've taken 3 pregnancy tests (1 a week and a half ago, 1 a week ago, and 1 today.) All were negative.

2 weeks before my period, I had mild cramping and spotting, but definitely not enough to qualify as a light period.

Yesterday, I had light pink and brown spotting throughout the day. I've been very tired and a bit light headed recently but I had summed this up as me starting a new job, normal stress etc.

I'm young and I've never been pregnant and frankly reading on the internet has been terrifying me. Does it seem to anyone that I'm pregnant, despite the negative tests?

NOTE: my periods have ALWAYS been regular in the past.