Suggest Medicine To Delay Periods

I want to delay my period due to wedding and honeymoon. I was told that I can take duphaston, three pills a day in the morning and I can stop when I wish to see a period. In total I will have to take the pills for 23 days. I wish to have and a second opinion on this. For how long can a take duphaston? How many pills per day? Can I take them for 23 days? Are there any side effects?