Sir, My Menstration Date Was On August 10.Me And My

Sir, my menstration date was on August 10.Me and my boyfriend made sex on august 6th..He didn't insert inside me,but I swallowed his semen a lot.after that menus has not happened.this was the 6 the day after menus date.his semen didn't got inside my vagina.may be a chance for rubbing in my vagina.is there any chance for pregnancy..or my menstration date extended due to swallowing of semen