Could I be pregnant? Please help

hi, here's my dilemma-

pregnancy symptoms like sore boobs, nausea, tiredness and being really put off food hit me about 2 weeks ago. I took a test and it came back negative, obviously I was distraught. I was due on my period on the 23rd but didn't have any signs of blood until the next day- I suffered from period pain and bled heavily which led me to accept that I am not pregnant. the next day I was still bleeding, regular period. yesterday I hardly bled at all and today I've had one or two spots of blood. my period is normally always on time and 5 days at the least. I still feel very put off food and feeling sick. I get these strange headaches a few times a day which don't last long but aren't pleasant. I'm really struggling to sleep but feel exhausted. I am trying to not take a test to avoid the dissapointment, has this ever happened to any of you or know anyone who has experienced this while pregnant? could stress cause this also? I will really appreciate anyone who could take some time to answer this or give me some advice. 

young, lonely, confused and scared.