First month of Oestrogen patches + Utrogestan & my period has turned up at wrong time. Has this happened to anyone else? How did you cope?

[Koala365]

So I started my oestrogen patches on the first day of my totally regular 28 day cycle and my utrogestan tablets on day 15 foe 14 days as prescribed but on day 21 (the first day of my holiday- oh lucky me!) my period turned up and stuck around for a good 6 days. I will stop taking the tablets on day 28 (today). But now I am confused. Presumably suddenly removing progesterone will signal to my body that I should now have a period and I will suddenly have another period. Whether that happens or not I guess I just continue counting the day after the last tablets as Day 1 and then start the tablets again on Day 15. Anyone else been here? What happened and how did you cope?