Birth control question

I was put on a lower dose of my combination birth control because my blood pressure was high. I have never missed a dose. I am on the last 2 pills of the low dose pack before I go back to the higher dose combination pack (since we decided it isn't my birth control causing it to be high) Anyway, I have been on the higher dose (the one I am going to start again) for at least 3-4 years. My question is since I haven't missed or pill or been off birth control am I protected? I will still use a condom my Obgyn never informed me of the effectiveness switching between pill packs.