If I'm taking Norgestimate And Ethinyl Estradiol, a contraceptive, and minocycline for my acne (100 mg), is there a heightened possibility that the contraceptives will fail and I could get pregnant if having sex? If so, by how much percent is that chance increased?

There is not a percent, like 10 percent or 20 percent, it can, cause it to be less effective. The issue is, you do understand, the birth control is not 100 percent effective to start with. So even perfectly, there is a chance of pregnancy.

Also, if it is just a one percent chance, that means 1000's of women get pregnant like that, you can easily be that one percent.