Pregnant or Imagination???

I was wonderin if I could be pg? I hav been havin some weird stuff happen to me lately. I had on April 28 and had my period before that on the 26th, then had another period on late afternoon may 13 very lite, then on may 14 it was kinda normal, but it stopped completely by early, early mornin may 15. I spotted a brown discharge about 4 days after . I’ve been having lower backaches, lightheadness severly, having to pee more, my look different, I look swollen down there, my stomach has been upset a lot, heartburn, feeling extremely sleepy, moodswings, and am majorly irritable. My boyfriend has asked me 3 or 4 times if I’m pregnant, and a few of my friends have asked, and 3 of my closest friends think I am, and my mom told me that she thought I was gonna get pg b4 my next bday and said I would b next to tell her im pg…Im in college and rly need to know wat the possibility is tat im pg?? I dont want to buy an hpt unless theres a rly good possiblity that i am pg...