As a high school student in Uganda, Cleopatra Kambugu said she knew she was different, but she didn’t know of any word to describe what she was. 

Biologically born male, Kambugu said she faced bullying and abuse in high school as she struggled with her identity.

"It was hard, I didn't have language for being called transgender," Kambugu told CTV's Canada AM on Friday. "I just knew I was different, and I didn't have a 'what' for it."

Kambugu, the first out transgender woman in Africa, and her partner Nelson Kasaija, are the subjects of the documentary "The Pearl of Africa," which premieres this weekend at Toronto's Hot Docs festival.

Kambugu said her family didn't deal well with the fact that she was quietly participating in LGBT activism in Uganda, where the vast majority of the population is against homosexuality .

"My family took my being transgender as a pathology, as something I shouldn't talk about openly, as something I shouldn't be proud about," she said.

In 2014, Kambugu was publicly outed on the front page of one of Uganda's largest tabloid newspapers. The tabloid printed a list of what it called Uganda’s ‘top’ homosexuals soon after the country's president signed an anti-homosexuality act into law that criminalized same-sex relationships.

"They only allowed me to stay in Uganda up to the point when that anonymity was broken, and then they couldn't deal with that anymore," she said.

At the time, Kambugu was enrolled in a master’s program and working with the Ministry of Agriculture on molecular biology and Kasaija was working at a public hospital.

Kambugu said she was fired from the ministry and Kasaija said he couldn't go back to his job out of fear he would be ridiculed. 

The couple say they didn't have any choice but to leave Uganda out of fear for their and their families’ safety.

They fled to Nairobi, where Kambugu now works with an organization that supports LGBT rights in Africa.

"I was happy," she said. "I still wanted to contribute to the movement."

However, both Kambugu and Kasaija hope to one day return to Uganda.