It all started with me spotting light brown for a day or so, then it turned in to light pink for about two days. I have had lower back pain , cramps , dizzyness, tiredness, nausea , and headaches . I have taken two pregnancy test that have both come up negative. I don t have regular periods. I haven t had one for a few months now. So it s hard to go by when my period is going to be here on when I should take a home test.. What do you think could be my problem?