Farrah Abraham was arrested on March 18 for drunk driving in Nebraska, but now, the Teen Mom star defends her actions exclusively to In Touch, opening up about the details of her DUI arrest.

“It was St. Patrick’s Day and I was out with my sister. I did not plan to drink because I was sick, so I took the role of being in charge and making sure my sister and I would return home together and safely,” Farrah, 21, tells In Touch. “At 10 p.m., I tried to leave, and at that time, my sister was not ready to leave, so I had been sipping on drinks to pass the time.”

NEWS: Farrah Abraham Arrested for Drunk Driving

Farrah goes on to tell the mag that her sister was ready to leave around 12:30 a.m. but refused to walk to the car, as she was hoping to leave with someone else. To avoid an argument, Farrah went to retrieve the car with plans of picking up her sister when she noticed a heavy police presence in the area and chose to park the car at her own will.

“When I was parked, a police officer asked me what I was doing, so I told him I was worried about my sister and I was trying to go home,” Farrah tells In Touch. “They insisted on the regular questions and asked me to get out of the car. I got out of the car, and because I was upset, I yelled.”

EXCLUSIVE: Farrah Defends Her Parenting Decisions to In Touch

Moments later, Farrah was administered a breathalyzer test by the police, which revealed a blood alcohol level of .147 – almost twice Nebraska’s legal limit of 0.08.

But, according to Farrah, it was her illness that had a negative effect on the test’s results.

“Because I'm sick, I could not give an accurate breathalyzer test, due to coughing and shortage of breath,” the reality star says. “I have a lawyer and all will work out with my ticket.”

For more on Farrah’s DUI and the details of her arrest, pick up next week’s issue of In Touch — on stands Wednesday, March 27.

Have a tip? Send it to us! Email In Touch at contact@intouchweekly.com.