You should be able to delay the onset of your menses till after the trip. Usually we will recommend starting to take some hormone pills at least 3-4 days prior to your menses, and to continue throughout the trip, till you are back.
Once home, you can stop the hormone pills and then your menses should come within the next 1-2 days.
You may get some minor side effects like water retention, feeling of bloatedness, occasionally headaches or slight mood change etc. Usually the chance is low given that we are giving a low dose hormone pill and the side effects will resolve once you stop it.
You may see either a GP or Gynaecologist to get the hormone pill. Please note that the hormone pill is not meant to be contraceptive in nature in this instance and it does not stop ovulation or prevent pregnancy.
Have a good trip!
Best regards
Dr YF Fong