I Wish To Delay My Period For About 3-4 Days

I wish to delay my period for about 3-4 days by using Premount N as I have to go away on a holiday. My period is very irregular and my due date is right on the day I leave. So i'm just wondering is it possible for me to delay it for about 2-3 days only.So i want to know is it will be safe for me to take this medicine. Also I read after I stop the medicine my period will come 2-3 days later so give me some idea about this? Thank you!