It should have been the happiest time of Theresa Patchen’s life. Newly married and eight months pregnant, she certainly wasn’t expecting to hear the news any woman would dread: that she had breast cancer.

In a matter of minutes, Patchen’s emotions changed from happy and excited to fearful.

“The surgeon wanted to do a double mastectomy, the oncologist wanted to start chemotherapy – but I was still eight months pregnant,” Patchen told FOXNews.com in a phone interview. “Within a week, I was admitted to the hospital and they took my son by C-section.”

On May 25, Patchen, 33, of Waterloo, N.Y., delivered a healthy baby boy named Joseph Timothy, but her joy would be short-lived.

“At first I had a fear of not being around to see my son, but once I saw the pathology report, my fear was of the chemotherapy,” Patchen said. “I was petrified, and sad about the mastectomy. I wanted to nurse my baby. I couldn’t hold him for over a month. I couldn’t feed him or pick him up.”

October is National Breast Cancer Awareness Month, and Patchen is just one of the 240,000 American women who will be diagnosed with the disease this year.

Each year, 40,000 women in the United States die of the disease, which does discriminate – in comparison about 2,000 American men will be diagnosed with breast cancer this year. Of those, just 400 will die.

Patchen believes her cancer started before she became pregnant. In November 2006 she noticed a lump in her left breast while honeymooning in Las Vegas. She called her doctor to schedule an appointment upon her return.

“I had never felt anything like it before,” she said. “My paternal grandmother and her sisters, three of them, all had breast cancer. It was a paranoia I always had.”

Patchen underwent a mammogram, but her doctor dismissed the lump as a harmless cyst and said she had nothing to worry about. By the following September, she was pregnant.

But when she woke up in mid-March to see a mass the size of “half a tennis ball” literally poking out of her breast, she was worried.

By that time, it was too late. Patchen had stage IIB cancer in both breasts.

Stage II breast cancer can mean one of two things:

a) The tumor is larger than 2 centimeters, but not larger than 5 centimeters and has spread to the axillary lymph nodes, or

b) The tumor is larger than 5 centimeters, but has not spread to the axillary lymph nodes.

The tumor in Patchen’s left breast was 6.5 centimeters, which is the size of a lime, and the tumor in her right breast was 4.1 centimeters, the size of a walnut.

A woman in her 30s has a 1 in 250 chance of developing breast cancer compared to a woman in her 40s, whose risk is 1 in 70, said Dr. Cynara Coomer, a breast surgeon at Mount Sinai Medical Center in New York City.

Patchen began her chemotherapy treatments in July, which will be followed by a course of radiation.

She took a leave of absence from her teaching job, but said she plans on returning in February.

One week after her first chemotherapy treatment, Patchen and her fraternal twin sister, Samantha Prayne, shaved their heads.

“There was no way I could have just sat there,” said Prayne, who lives in nearby Seneca Falls, N.Y., and is also a teacher. “My husband was fine with it, but a few of my friends said I shouldn’t do it. I had to.”

Prayne decided not to wear a wig, while Patchen wore one similar to her own hair.

“She didn’t have a choice to get cancer,” Prayne said, choking up. “So, it was the least I could do. I tied a pink bandana around my head for the first four months. It’s hair, it’ll grow back.”

In September, Patchen tested positive for a deleterious mutation of the BRCA1 gene.

Woman who test positive for this mutated gene have an 87 percent chance of developing breast cancer, and a 40 percent of developing ovarian cancer, Coomer said.

Patients often undergo BRCA testing even after they have been diagnosed with breast cancer, Coomer said, because a positive mutation could indicate the breast cancer will return, prompting the patient to undergo a bilateral mastectomy.

Some breast cancer patients who test positive for the mutated gene also opt to have their ovaries removed, Coomer said.

For Patchen, there isn’t even a question of whether she will do that.

“Definitely,” she said.

Prayne has yet to undergo testing to see if she carries the gene, but she plans on doing it within the month. She said she is uncertain of what she will do if the test comes back positive.

“I would like to have more children, so that will be a factor,” said Prayne, who has one son and one daughter.

At this time, Patchen has chosen to not have reconstructive surgery. Her doctors did not want her to have the surgery so soon after the mastectomy because it would delay chemotherapy, and once she is done with radiation, she isn’t sure she wants to go through another painful process.

“I was afraid of looking completely butchered, but my surgeon was phenomenal,” Patchen said. “I’m getting more comfortable, and my husband Tim has been unbelievable. He’s been an amazing support.”

In the midst of her tears, Patchen has never once questioned why she was the one struck with such a horrific disease.

“She is not curled up in a ball saying ‘why me’?” Prayne said. “She is getting on with her life, and has made it her mission to raise breast health awareness.”

Patchen’s trials are from over. She remains optimistic: Stage II breast cancer has an 86 percent survival rate – and she has every intention of seeing her son reach the important milestones in his life.

And, maybe just as importantly, she has lives to save besides her own.

She may not be able to go back to 2006 when the doctor told her not to worry about the cyst in her left breast, but she hopes other women will take something away from her story.

“What did I know when I skipped out of the hospital at that point? If you feel something is not right, don’t stop until you are comfortable,” Patchen said. “Young breasts are so dense, so if something is detected, demand an ultrasound or something that will examine further. Forty is not a magic number – you can get breast cancer at any age.”