Just about to start BC

Rachel • In love❤️ blessed beyond belief 🙏🏼
My doctor prescribed me tri sprintec and its my first time on the pill. However, my period is 5 days late because I've had to take the morning after pill 3 times in the last two weeks because of some accidents. Should I wait until I get my period to start my pack of BC pills, or can I just start today? I appreciate any thoughts!