Is within a birth control that will start working NOW?

If I am on birth control for a little smaller amount than couple months, will it be fully effective within preventing pregnancy? If not, would the nuva-ring be immediately decisive? Help me, please. My boyfriends deployment was cut shorter than it be suppose to be so hes coming home SOON! You can be pretty assured with a cycle's worth of birth control used correctly, but tons methods state that you are protected after one week (check the paperwork, fine print, or website of your particular method).
Of course, both the manly and female condoms are in a jiffy effective.
But if you've be consistent and correct in your use, you should be pretty capably protected after a complete cycle. Bear in mind that this is beyond doubt dependent on your following the directions exactly.
Best to call your Dr. for his/her evaluation.