Is my birth control protecting me?

I’ve made a few posts with little help, so I really want to try to make this short. I started a new brand of birth control pills a week after finishing my last brand and still have not gotten my period (I’m supposed to on this type of pill). It’s been almost 3 months, and I’ve been through 3 packs of birth control. I don’t go back to the doctor for another 2 weeks and just got to wondering. Is my birth control even effective against pregnancy if it isn’t working well enough for me to receive my period? Also, will I still ovulate if I do not have any periods? I’ve had unprotected sex several times which is a cause for concern. TIA.