I would agree with the others it takes a while for your cycle to get back to normal and sometimes normal is not the same as it used to be, I went from a 28day cycle with a 7 day period to a 21 sometimes longer with a 3 day heavy period.
Treat this cycle as all fresh and enjoy your holiday, it's usually when you relax that it all falls into place.
I have had a series of MC's and my cycle always was messed up after that and they were all around 3 months or less so going full term you would imagine messes with it even more add to that BF and BC pill.
Good luck and enjoy your holiday!!!!!