Began Depo-Provera 2/12 next shot 9/12 & none after that, unpro sex. 1month ago I started having tender breasts nausea hot flashes dizzy. Preg or period coming?

Unprotected sex. U should not have unprotected sex unless u want to be pregnant , otherwise u can expose u self to sexually transmitted disease and unwanted pregnancy and both r bad choices.
Symptoms. Could be either. You should do a pregnancy test. If you are pregnant from unprotected sex a month ago, it would be positive by now.