๐Ÿ˜•๐Ÿ˜• confused

Has anyone ever gotten pregnant on birth control? I had my period shortly after an incident (as expected with the birth control) however... the last couple days Iโ€™ve been experiencing some weird symptoms. I have had severe constipation, gas, and burping. My throat is on fire and I constantly feel nauseous. On top of all of this my boobs are slightly sore and I am also having hot flashes.