Hi I Am 12 Years Old And Think I Might

Hi I am 12 years old and think I might be pregnant . I've never had sex or even had a boyfriend. I think I'm pregnant because I have had a vibrating sensation coming from my uterus. I also have noticed my vein are enlarging ang my heartbeat is noticeable from my breasts. I've been getting hot flashes and slight nausea. I also have all the symptoms of an ibs and the other day as I sat on my bike I had a intense pain in my rectum and vulva. I don't know if any of this has to do with possibly being pregnant but I'm really scared. My last period was on 6/20/15 and today is 7/4/15. My period lasted about 7 days until it ended completely.