Over the past month, United Airlines has been rocked by a string of highly charged incidents between airline employees and customers.

This week, a Missouri woman decided to step forward with another one.

In a lengthy post on Facebook, Nicole Harper — an emergency room nurse who says she suffers from an overactive bladder — claims she was forced to urinate in a cup during a Mesa Airlines flight from Houston to Kansas City, Mo., last month after flight attendants refused to allow her to use the restroom.

Mesa Airlines is a regional U.S. carrier that has operated as United Express for more than two decades.

Attempts to reach Harper were not immediately successful.

On Facebook, Harper referred to the incident as “the worst flight I have ever been on” and noted that it occurred the same day that a 69-year-old passenger was dragged off a United flight beaten and bloodied — for refusing to give up his seat for a crew member.

United Airlines said a man wouldn’t give up his spot on a flight. According to witnesses, he was pulled screaming from his seat by security and back to the terminal at Chicago’s O’Hare International Airport. (The Washington Post)

“As an emergency room nurse, I completely understand having a bad day on the job and having to deal with undesirable bodily fluids,” Harper wrote on Facebook. “What I don’t understand is ZERO customer service, if I treated a patient this poorly I would surely have consequences…”

United acknowledged that Harper ended up peeing in a cup but says it was her decision — not the airline’s. In a statement, the airline said Harper attempted to visit the restroom during the plane’s descent and was told to remain seated, with her seat belt on.

A United spokeswoman said the airline is investigating the incident but declined to comment more specifically on the alleged details or the status of the airline’s investigation.

“Customer safety is always our first priority,” the spokeswoman said. “Initial reports from the Mesa Airlines flight attendants indicate that Ms. Harper attempted to visit the lavatory on descent and was instructed to remain seated with the seat belt fastened, per FAA regulations. At no point during the flight did flight attendants suggest that Ms. Harper use cups instead of the lavatory.”

“We have reached out to Ms. Harper to better understand what occurred and we continue to review what happened,” the spokeswoman added.

Harper’s account and the airline’s account differ significantly.

She says the incident happened midway through the flight, while flight attendants were handing out drinks, not during the airplane’s descent.

Harper said that although the pilot had turned on the seat-belt sign — instructing passengers to remain in their seats — United crew members allowed other passengers to use the restroom. When she tried to explain that she had an overactive bladder and would either need to use the restroom or use a cup, she writes, a flight attendant handed her two cups.

Harper told CBS affiliate KCTV that she was wearing a dress at the time and — with the assistance of her husband — she was forced to squat over her seat and relieve herself inside both cups.

“It’s so degrading because there are passengers, strangers, that I have to basically do this in front of,” she told Fox affiliate WDAF-TV.

Harper says crew members escorted her to the restroom to empty the cups and stated that they would be filing a report and calling in a hazmat team to clean the row where she had been sitting, treating her like she “had committed a crime.”

“You would think peeing in a cup on an airplane in front my family and strangers, would be the worst part of this story,” she wrote on Facebook. “But the way I was treated by the flight attendants afterwards was worse. They were absolutely horrible to us the rest of the flight!”

“And to top it all off, once on our final descent … a gentlemen got up from first class (yes the seat belt sign was on, and the plane was flipping tilted) walked right by a smiling flight attendant and entered the bathroom,” she added. “What!?!?! Was I on candid camera? Where are the cameras right now!!!”

Harper wrote that she decided to step forward after United customer service agents refused to return her calls, although she said she hesitated because she doesn’t “want to be known as the ‘girl who peed in a cup.’ ”

In a subsequent Facebook post Tuesday night, she wrote that an executive customer-service representative at United finally called her after a local story about her incident aired.

“Rest assured, I will no longer be flying united, I will be cancelling our credit card, and I am hoping this goes viral,” Harper wrote in her original post. “Because, quite frankly this was the worst flight I have ever been on and there are plenty others to choose from, others that treat people with human freaking decency.”