Thanks for your query.
It is not necessary to experience nausea
with the pill, though it is a common side effect.
Also, with the intake of emergency contraceptives, your normal period might be preponed or postponed by a week or more.
You might also experience irregular spotting / bleeding anytime in between.
You should take a pregnany test if you do not have your normal period 4 weeks after the episode of unprotected sex.