I am experiencing pregnancy symptoms. My period was supposed to start on the 13th of March 2018 but did not come. All I got was very light bleeding that was brown in colour and was not even enough to fill a pad. I am on the pill and my period is supposed to last four to five days and is more red in colour. I feel dizzy, nauseas, tired, more hungry than usual, a little irritable and my breasts are itchy. I have taken several tests which have come back negative. I am currently experiencing some bleeding which it very light, brown in colour and only when I wipe. I have some occassional lower back aches too. My question is: what is wrong with me?