Melissa Pont, 23, said her family practitioner, Dr Joseph Lee, would not renew her pill prescription, instead lecturing her on a baby's right to live and on using the rhythm method, an unreliable family planning technique that involves having sex only at certain times of the month.
The Women's Health Action Trust said it has a "simmering issue" with GPs who will not prescribe contraceptives.
"Contraception is a basic health right for women," said senior policy analyst George Parker. "That should take precedence over a doctor's personal beliefs."
The NZ Medical Association said doctors can refuse treatment in non-emergency situations if their beliefs prohibit it - but they are required to refer the patient to another doctor.