Hi Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern...
Nausea & vomiting post unprotected sex could also be contributed to getting pregnant.
Pregnancy cause elevation of
progesterone hormones in body which could cause these symptoms like nausea, vomiting,
morning sickness, increased food hunger etc.
However many of these symptoms could be caused by food poisoning or
stomach infection as well. But morning sickness & increased hunger should not be there. In fact, stomach infection should cause decreased hunger & not feeling to be eating anything. Also stoppage of diarrhea or even
constipation should mean that the infection you had is now treated.
You should definitely get your self checked for pregnancy by doing a pregnancy test. Pregnancy test is easy & could be done at home by using a home pregnancy test kit. Follow instructions on pack.
Refer to a physician, if you are not pregnant
Hope this information helps