I had sex without protection and im on my period but this whole week i wanted to throw up, could i be pregnant?

Unlikely: If you were on your period it's unlikely plus you shouldn't be nauseous already.

Extremely unlikely: Having a period is usually a pretty good indication that you are not pregnant. Nausea is a nonspecific sign of pregnancy and can be caused by many other things, including being stressed out. Relax. Try drinking some Canada Dry Gingerale for your upset stomach. If you are not doing anything to prevent pregnancy, you should be taking Folic Acid every day, which helps to reduce birth defects.