The woman testified in the Johannesburg High Court last month that Makhubela had infected her with HIV-Aids when he allegedly raped her in 2009.
She said she was HIV-negative before the alleged rape and only tested positive afterwards.
"I can neither deny nor confirm her allegation because I don't know my status," Makhubela testified yesterday.
Together with his 50-year-old father, Makhubela faces 40 charges that include 17 of rape, assault and robbery, as well as kidnapping.
It is alleged the father and son posed as taxi operators to lure desperate women looking for transport at night. After the women had boarded their minibus taxi, they would then rob and rape them.
They have pleaded not guilty and said that the sex had been consensual.
Makhubela told the court that one of the women was a prostitute and that he had paid to have sex with her. "She said she would charge me R70 if I used a condom and R150 if I did not. I then opted for the no-condom romp."
He said he was not aware that the woman was five months pregnant because her tummy was not big. He also insisted that she slept with him for R50 because she was a "whore".
Makhubela also shot down the woman's testimony that his father was driving the taxi when he, allegedly sitting behind the driver's seat, raped her at gunpoint. "I was driving and she was seated next to me in the front seat. While I was driving, she kept touching me on my private parts, and I told her to stop as it was dangerous."
Makhubela said he found a safe spot where he stopped and they had sex. He claimed the victim was angered by the fact that his condom had burst.
The trial continues.