al negative tests but alot of headaches!!

i had sex with my boyfriend about 48 days ago ((maybe longer havent counted)) And i had my 2 periods which were like a week early but thats normal and they were heavy, never got morning sickness, and all my tests have been negative. I've even aken alot of tests and they've all been negative. My last test was last monday morning, they all say negative. But im scared that i still am cuz i keep havin little headaches
and i've heard that u get headaches like that through out the day as an early symptom
and i was just wondering if u would think i was or not
i think my headaches are bein caused by stress and cuz my next (3rd since sex) period is in about 2weeks so i always get headaches b4 that

but do u think im pregnant after all them tests saying negative??