Although it was only revealed a few weeks ago that Christina Applegate had been diagnosed with breast cancer, the actress now admits that she found out back in April.

In an exclusive interview on Good Morning America, the Samantha Who? star told Robin Roberts (also a breast cancer survivor) that her vigilance really paid off in in the end.

Because of her mother’s history with the same disease, Applegate knew it was important for her to begin mammograms at an early age. The 36-year-old had been receiving regular testing for approximately 6 years. Thanks to two MRIs conducted after a biopsy last year, the discovery was made.

Even though the cancer was only discovered in one breast, Christina made a difficult decision. After being told that she had tested positive for the breast cancer gene (BRCA1), the Emmy nominee opted not to go the chemotherapy/radiation route. She instead chose to have both breasts removed.

“My decision, after looking at all the treatment plans that were possibilities for me, the only one that seemed the most logical and the one that was going to work for me was to have a bilateral mastectomy. So basically I had a prophylactic double mastectomies.”

Applegate said she made her choice in hopes of giving herself some peace of mind.

“I didn’t want to go back to the doctors every four months for testing and squishing and everything. I just wanted to kind of be rid of this whole thing for me. This was the choice that I made, and it was a tough one.”

Three weeks after the surgery, Christina - who intends to have reconstructive work done -  is happy to say that she is now cancer-free. “I’m clear. Absolutely 100-percent clear and clean.”

Applegate will next be seen on September 5th during the Stand Up 2 Cancer telethon airing on ABC, NBC and CBS. After that, she can once again be seen on Samantha Who? when it resumes on October 6.

(To see that interview with Robin Roberts in its entirety, click here.)