Could i be pregnant or is it something more serious?

Ok, my las period was June 2nd. I had been sexually active right before my period, once during my period and once after it was over. I should have gotten my period today but I have no symptoms of my period coming. Bout a week ago I was kind of cramping a little. I have been having quite a bit more discharge than usual. Anyway, I also have a really itchy nipple. Well both are starting to itch but mostly the left one. I don't like to scrath it so I just press hard on it or squeeze it to try easing the itch. I think there could be a possibility of being pregnant eventhough people say I can't get pregnant yet because I recently stopped takin birthcontrol. I was getting the shot, they say you can get pregnant like one year after you stop. I was only on it for the 1st 3months. So who knows. Now, my question is could I be pregnant or can it be something more serious? I was doing some research and they mention breast cancer. My mom is a breast cancer survivor. They detected breast cancer in her at age 37? Her breast cancer dr told me that at age 26 or so I should get checked because I run the risk to get breast cancer since cancer runs through my moms and dads families. I'm kind of worried, I'm 21yrs old btw. Please any help!? Thank you!