(Help me!!!) Birth control pill norgestimate ethinyl estradiol tablets usp

So I'm 19 years old, first time ever taking birth control and I heard you suppose to start on a Sunday but I didn't take it yesterday can I start today? Which is Monday.. If so do I take the Sunday pill today too plus the Monday pill? And I'm not on my period I finished my period like 3 days ago HEEEELLLLLPPP