So according to my period tracker app my period was supposed to come on the 3rd....and still no…

So according to my period tracker app my period was supposed to come on the 3rd....and still no signs of it....its very hard for me to get comfortable while trying to sleep the past few nights, my entire body hurts all day long, and im extremely tired....the only thing is, I cant determine if its possible 2nd pregnancy or if its going to be my period! 😮 i need opinions!