that is highly unlikely.
it sounds like your stressed about whether or not your pregnant, and stress can cause periods to be late.
also, your thinking ifyou are pregnant, and the thought of 'could i be' can make our brains to think 'yes i am pregnant' and give us pregnancy symptoms, when really there is no pregnancy happening at all.
take a pregnancy test to be sure your not, and maybe get on some birth control pills or dont have sex until you know all the consequences of having sex.