So I usually have regular periods, my period is now a week late, I feel really sick, constant headache, feel tired and just not myself really so I did a pregnancy test and it was negative, checked the next day and it had a blue + but was reall light. I'm not sure what to make of it, every other time I've done a pregnancy test and checked the next day It still says negative. Never been pregnant before so I'm really unsure on how I should feel. I've just done another test but that's come up as negative. Which one is correct? I've heard there can't really be "false positives" but "false negatives" are possible.