Me an my boyfriend have been having for awhile, i need help deciding if maybe i could be pregnant.?

We have been having frequent for over a month. He had to help his family in Alabama and was going to be gone for awhile so we decided to have lots of before he left. We used a condom Most of the time, and admittedly we have an unusual issue with condoms breaking, but never during ejaculation... It has been between 3 and 4 weeks and i am feeling nauseous, dizzy, exhausted, and i get terrible heat flashes. I am also eating a whole lot more than usual and im getting strong cravings for certain foods. Could this just be a stomach flu? What are the chances of me being pregnant?