Macrobid does not affect the effectiveness of birth control pills. You continue to take your birth control through your whole cycle there shouldn't be a concern.
Oh my. You are clearly very anxious. You used condoms, are a 'perfect birth control user' and took plan B. Plan B is a major whopping dose of hormones. It's going to throw your system off. Holy hormone overload! I think you are protected from pregnancy but in situations like this, you should get guidance from your doctor. You don't want to do more harm to your system by overdoing the anxious pregnancy prevention! Remember, timing of the sex within your cycle is also a huge factor in conception. Have you talked to your doctor about anxiety symptoms? I'm not minimizing your concerns about pregnancy, nothing is 100 percent safe from pregnancy but not having sex. But you seem like anxiety may interfere with your peace of mind and that is very treatable. good luck sweetie
From what you describe, your unprotected sex did not even involve ejaculation, so the chances are really slim, next to none. It IS possible to get pregnant if taking antibiotics while on BC pills, but you should be safe given the condom usage and plan B.
The throwing up could be due to something else. In any case, not all women throw up right at the beginning of a pregnancy. It takes a few weeks for pregnancy morning sickness to kick in usually.