I'm always nervous at airports.

I'm a teenage girl, no interest in smoking or consuming any drugs, including alcohol, but whenever I am at the airport, I get nervous that drugs will be found on my body or in my bags, or even that the beeping thing will go off when I walk through it.
On the weekend I went to a party, and guys were smoking drugs around me and now I'm freaking out that when I'm at an airport, I'm going to get tested positive fro drugs. Will this actually happen, or am I being paranoid?

Your fear is unfounded. The pre-flight screening at the airport is looking for weapons and explosives on your person or in your carry-on. It's not a drug screening test and does not detect drug use nor drug odors.

Make sure you are familiar with what you can carry on. There's a list of banned items at the link below. On some browsers you may have to scroll way down the page to see the list.

http://www.tsa.gov/traveler-information/prohibited-items