My period ended on 11/29/16. My boyfriend and I had sex on 12/1/16 and since then I've started having back pains, low abdominal cramps, headaches, I've felt tired and certain smells have made me feel nauseous. We had sex again 12/6/16. I know it's way to early to know if I'm pregnant but I'm having some early signs that I am. Please help..