Sara Mujica, a 17-year-old from Connecticut, was visiting her fiancé, Victor Cruz, in the Honduras where he lives.
When she took her pregnancy test in March, she was getting over an illness that gave her rashes, headaches, and neck aches - but she thought it was related to fish she had eaten.
However, just to be safe, the teen went to hospital to get tested for Zika.
She later discovered that a chance mosquito bite had left her infected with the illness - and that her baby could be affected as a result.
Sara told the Associated Press: "I was in a state of shock honestly… I didn't really know what to say. I didn't know what to do.
“I just started getting teary eyed and almost crying. I was just trying to stay strong."
The Zika virus is a disease caused by an infection that is carried by a certain type of mosquito, but experts believe it may also be spread through unprotected sex with an infected person.
After becoming an epidemic in Latin America, the World Health Organisation has said that the illness poses a global public health emergency - mainly due to how it can affect pregnant women.
Sarah Redshaw, Managing Editor of BabyCentre UK, explained to us: “If contracted during your pregnancy, it could increase your risk of microcephaly – a birth defect where the baby’s head is smaller than usual, often with a smaller brain that may not have developed properly.”
There is no vaccine or specific treatment available for Zika virus.
Sara, who is Catholic, has decided to keep her baby, whom she refers to as her “miracle” - prompting many to slam her behaviour as “selfish” and “unethical”.
One wrote: “You are a selfish attention w---e. Shame on you. If you were a real mom and loved your child at all, you wouldn't put an innocent life through what's ahead.
“Begging people for money to pay for your poor choices just makes a bad situation worse. So sad.”
Another added: “You're being selfish and opportunistic. You should abort the foetus before it becomes another burden on society.
“Also if you're fine with premarital sex then you can't use religion as an excuse not to abort.”
However others have defended Sara, with one writing: “Every baby is a miracle - keep up the positive attitude. Ignore all the hateful comments because no one is perfect.
“I wish nothing but the best for you and your little family.”
Sara, meanwhile, has hit back at her critics.
She wrote: "This is my blessing. This is my miracle.
"I have a cousin who has Down syndrome and he is so smart and l love him so much. I would never give up a Down syndrome child or a child with birth defects.
“I’m going to stay positive and hope my baby comes out normal."
Sara, who is one of only 44 women to get pregnant with Zika in the USA, has set up a Go Fund Me page to help raise money for her unborn child.
Writing on the page, she said: “Being young and pregnant is one thing, but now I am still pregnant and young but going through the worst time ever with the news about me having Zika.
“Every donation will be helpful and I am so grateful.”
You may also wish to read - The Zika Virus: Causes, symptoms, and dangers for pregnant women.