I had sex a week after my period however my period before last, from June 16 to the first of July. Therefore my bf said it would come late. It did but my stomach has a shape or form . Could I be pregnant?

As you are mature enough to have sex, clearly you understand that anytime you consent to have sex, you are consenting to any of the possible consequences.  I have no idea if you are in fact pregnant or not but I'm certain you will deal with whatever comes you will continue making the good adult decisions that you normally do.