If you are taking cerazette
for 2 month regularly then no need to worry. As it is contraceptive
pill, it is unlikely that you are pregnant.
Nausea and vomiting could be because of indigestion
When women start oral contraceptive pill, bleeding pattern changes- it could be either less/more flow. It will take around 6-8 months for your body to be regular.
Still if thought of being pregnant is bothering you too much, just get urine pregnancy
done at home. This will relieve your stress.
I hope I have answered your query.