What would cause me to get my period twice a month even though I'm on birth control pills and I take them correctly at the same time every day?

Maybe it's the pill. Sometimes women on birth control pills will have "breakthrough bleeding." that is unscheduled bleeding while taking the pill. If you're just starting this pill, give it a few months and it may resolve. If this is persistent, you may want to try another type of pill that will better control your bleeding. And, of course, take a pregnancy test to be sure that isn't the cause of irregular bleeding.