Should I Continue Progyluton After Completing 21 Days If My Period Hasn T Started On Day 5?

Hello Doctor,i am 32 yrs and single i started progyluton on doctor’ Prescription bcz i was having low flow issue during my periods..its my first time of tablets now i have cmpltd the 21 days tablets time and its my 5th day and I didn’t have my periods i m very worried..wat shud i do?? Should I continue on the 7th day or should i wait for my periods?