morning after pill - period 5 days after my last one?

Nadia
Hey guys I toke the morning after pill on Wednesday 12/04 & my period ended around the same time (it was super light by Tuesday but completely stopped Wednesday) & I've literally just started my period again this morning 17/04. 
I don't know if this is something to worry about?? I've currently got really bad diarrhoea and the doctors think it's a bacterial infection and told me to call back if I bleed heavily from anywhere I shouldn't be. I don't know if this would come under it because I'm assuming it's a period but I'm worried they're linked?!? 
Help 🙈