(Photo credit: Chelsea Lauren/Getty Images)

Jen Arnold is sharing more details about her ongoing cancer battle.

The star of TLC's "The Little Couple," told PEOPLE magazine that she was diagnosed with stage 3 choriocarcinoma, a rare cancer that formed during a non-viable pregnancy she had in September.

"The one time I get pregnant," she told the magazine, "I get cancer."

Why Jen Arnold Will Show Her Cancer Battle On TV

Arnold and her husband, Bill Klein, both 39, were in India with their son Will, 3, to pick up their daughter Zoey, 2, when Arnold began bleeding. After her OB-GYN advised her to return home to Houston, Klein stayed with their kids to finish necessary adoption paperwork for Zoey.

"My initial thoughts were all about Zoey," Arnold tells PEOPLE. "But then the bleeding got worse and I was feeling light-headed. It was a hard decision, but I had to go home."

"The Little Couple" Stars Discuss How Adoption Changed Their Lives

Ultimately, after chemotherapy failed to shrink the tumor in her uterus, doctors were forced to perform a hysterectomy.

"We wanted to avoid surgery in her case because of her shortened airway and the difficulties she has had in the past with surgeries," Dr. Concepcion R. Diaz-Arrastia, director of gynecology oncology at Baylor College of Medicine, who is treating Arnold, told the magazine. "But we felt we had no choice. The disease was not responding to chemotherapy. We had to do this in order to save her life."