Talk to Gynecologist on Menstural Cycle

I had my last periods on 17 of last month, as I was on a holy trip I took medicine to stop them and after 3 days of bleeding they stopped but I continued the medicine. After 3 days of stopping the med I had my periods again on 26 and they remained for whole 7days and were with proper flow.

My question is which date should I consider my period date the one that was before taking med or the one after I stopped the medicine?