I am a 17 year old female. Every morning when I wake up I am nauseous. It usually goes away by mid-morning. I have been having lower back pain a lot recently. Also my belly looks like it has gotten bigger. I was on my period on October 20. Two weeks after that I bled again, I think it was implantation bleeding. Today my boyfriend felt my belly and said that he felt something in my belly and that my boobs look different. I really think I'm pregnant. I took a pee test at the hospital like 3 1/2 weeks ago and it was negative but I can feel something in my belly

Try going to the doctor.