NEW YORK -- Actress Christina Applegate said that she had a double mastectomy three weeks ago following a recent diagnosis with breast cancer, and that she'll undergo reconstructive surgery over the next eight months.

The Emmy-nominated star of "Samantha Who?" said on "Good Morning America" Tuesday that she's "absolutely 100 percent clear and clean."

"They got everything out," Applegate said.

The interview was Applegate's first since announcing her diagnosis.

The 36-year-old actress said that she elected to remove both breasts even though the disease was contained in one breast.

"I just wanted to kind of be rid of it," Applegate said in the interview. "So this was the choice I made and it was a tough one."

Applegate called the operation a logical decision. Her mother battled breast cancer, and she tested positive for the BRCA1 gene mutation linked to breast and ovarian cancer.

Applegate said when she first found out she had breast cancer, she was so mad that she "was just shaking" but immediately went into "take-care-of-business-mode," asking all the questions about treatment.

The "Married With Children" and "Anchorman" star said that she began getting mammograms six years ago when she was 30.

Applegate is scheduled to appear on a one-hour television special, "Stand Up to Cancer," to air on ABC, CBS and NBC Sept. 5 to raise money for cancer research.