Trying to figure out my cycles

2 miscarriages back to back. This time I counted the day I started the miscarriage as cycle day 1. I figured I wouldn't have known I was pregnant if I didn't test early. The only reason I tested was because I was prescribed medication to bring my period back after the first miscarriage and it's not supposed to be taken if pregnant. Do you think it's OK to count it as cycle day 1?