Actress Valerie Harper arrives for the taping of "Betty White's 90th Birthday: A Tribute to America's Golden Girl" in Los Angeles January 8, 2012. REUTERS file photo/Sam Mircovich Harper reveals lung cancer battle Images: Valerie Harper

Cancer-stricken TV star Valerie Harper knew something was wrong with her health last summer when she first began feeling ill - but she ignored the warning signs for months.

The Mary Tyler Moore Show veteran, who played Rhoda Morgenstern in the hit U.S. series, was diagnosed with a rare form of terminal brain cancer in January.

She shocked fans by going public with the devastating news in an interview with People magazine on Wednesday, but the 73 year old admits the disease could have been spotted as early as August, when she felt this "funny little band" moving around in her midsection.

Then, about four months later, the actress became violently ill while running errands in California: "My windshield was obliterated with vomit, and I hadn't felt sick. Later I found out that is a benchmark for a seizure."

She finally went for a medical check-up in January after the right side of her jaw locked up as she was rehearsing for her one-woman play Looped. She explains, "I asked the director, 'Do I sound funny?' Tony (Cacciotti, my husband) came and took me to the hospital. They thought I had a stroke."

Doctors ultimately informed Harper of her prognosis on January 15, and the actress reveals she's been undergoing chemotherapy treatment ever since, stating, "I have a fighting chance until I'm gone."

However, Harper is preparing for the worst and has accepted her fate, adding, "I've had a good run. What more can I ask for?"

And she has already called her local crematory to get a head start on her own funeral arrangements, revealing, "I've been worried about getting stuff done before this (cancer) starts affecting my thinking and clarity."