so the lowest part of my tummy started aching last night, i had p.e yesterday and we were doing the Sargent jump, long jump from just standing still, flexibility test, the Illinois agility test and the strength, it hurts if i touch it and aches when i start to lay down, when i start to stand up, when i start to sit down and when i stretch, i know it's not period pain as i just finished 2 days ago, have i pulled a muscle or something?