hi. i have come off the pill 5 months ago i had regular periods since doing so. now i am late by 6 days. at my most fertile time i had a lot of sex. im now finding i am bloated, sleepy, feeling sick quite a lot, the color of my nipples have darkened and i have raised bumps on them. i bought a cheap test from tesco yesterday and it showed negative. does this mean im definatley not pregnant?