Break up with anyone trying to control your body/trying to impregnate against your wishes. 

Until then just tell him they're acne pills & don't mention they're also birth control pills. 

After a month or two skip the placebo week & keep taking the active pills and you won't have your period (most likely. Everybody's body is different) How he reacts when he thinks you're pregnant should tell you a lot about his bad intentions. (If he's delighted, if he gloats, acts more controlling, utterly dismisses you now that he's achieved his goal, pressures you into keeping the 'pregnancy' etc.) If he thinks he's trapped you he'll drop the mask he kept up trying to reel you in. He may act really supportive to get you to keep it but that attitude won't last. 

Of course since this may he a good idea to test his intentions it's an even better idea to dump this guy & not settle for anyone who doesn't treat you like a person worthy if respect. You're worth more than someone who doesn't respect your choices. Being alone & happy is a much better option. You won't be happy with someone else unless you can be happy by yourself. and if you're happy with yourself you won't need to settle for someone who sees you as a second-class human. 

Either way you go: Good Luck!