Blake, 72, married Bonny Lee Bakley, 44, after she got pregnant with their daughter, Rosie, now 5.
Bakley's children are suing Blake for their mother's wrongful death, even though he was acquitted in March of fatally shooting Bakley outside a Studio City, Calif., restaurant in 2001.
Bakley's oldest daughter testified in the Burbank court her mother took the fertility drug Clomid while dating Blake, KABC-TV, Los Angeles, reported.
"I told him I was on the pill. I just didn't say what pill. Ha, ha,"' Holly Gawron, 25, quoted her mother as saying.
Gawron said she also helped her mother scam men by calling bachelors and leaving recorded messages asking them to contact Bakley.
Earlier this week, Gawron told the court Bakley told her Blake said "he had a bullet with her name on it."