norethisterone to delay 12 year olds period

[MrsGreen24]

We are going on holiday on 7th May. My daughter is due on beginning of May but can't remember if it's the 4th or 10th. The doctor has prescribed norethisterone to take 3 days before she is due. Has anyone had any experience with this and any recommendations on when to take it. Was thinking the 1st but don't want to mess anything up for her cycle. Any advice appreciated.

i never heard of a teen being prescribed this i didn't realise you could even get it prescribed for that age. But from experience it delays fine but you get a super heavy awful period after would but then its fine come next period