Burst my incision ...help ?!?

just had abdominal hysterectomy five days ago - sneezed very hard today and felt a sudden rush of warmth and i dont know how else to describe it except a bursting sensation.... i have 2 sets of stiches one on the outside and one on the inside....the outside is fine, how would i know if i burst them and what will happen if i did? i will call the doc but its after office hours and there is no one on call, thanks for your input