possibly pregnant? or is there something really wrong with me?

me and my boyfriends been sexually active for about 6 months now, we have do not use any method of birth control, protection or even pulling out. my period has always been messed up, but for about a month it stopped. a few days ago i started bleeding it was a lot then it slowed down and stopped all of a sudden. today while having sex it started again, its not a lot of bleeding. for a couple weeks my boyfriend and i have been thinking i was pregnant. ive had cravings for stuff i wouldn't usually eat, my breast have gotten really big & my auroras around them have gotten really dark brown. my stomach & breast have been itching & they are getting really dry. i get this odd feeling in my lower abdominal and a really bad sharp pain. i get headaches all the time, early in the mornings i get a nausea feeling to my stomach & ive obviously gained weight in my stomach. i just get the feeling that im pregnant. im always feeling weak or achy. when i pee it really hurts & feels like something is pushing down on my stomach and i always feel like im going to pee.