i am 17 yrs old and i been having unprotected sex alot. Well i went to a party 2weeks ago and me and my bf had sex. but he dont know if he cummed in me. well the 18th and the 22nd of oct he cummed inside of me. i dont start my pd till the 31st. But i been having cramps, lower back ain off and on sleeping in class alot and boobs are getting bigger.

Is this a sign of pregnancy????