You had unprotected sex during safe period and took contraceptive
measures so chances of pregnancy
is least . After stoping of OCpills withdrawal bleeding occurs so no need to worry . vomiting is somtimes have side effect of vomiting .
So in my opinion confirm your pregnancy status through UPT if you don't get your menace after two weeks .Take anti emetic ( domperidone
.....)but if symptom persists or aggravates then visit gyne clinic for further management .
Thanks n regards .