OTTAWA -- The maker of the birth-control pill Alysena 28 has issued an urgent recall after it was discovered that one lot of the contraceptive may have been incorrectly packaged with only two weeks of drug-containing tablets instead of three.

Women taking the incorrectly packaged pill would not receive the proper amount of contraceptive, raising the possibility of an unplanned pregnancy.

In a recall notice distributed by Health Canada, Apotex Inc. said the product's 28-day blister packs should include 21 active birth-control pills plus seven placebo tablets that contain no drug.

Apotex said blister packs in the affected lot -- LF01899A -- may instead contain 14 placebo pills and 14 active contraceptive tablets.

Alysena 28 is sold in British Columbia, New Brunswick, Newfoundland and Labrador, Nova Scotia, Ontario, P.E.I. and Quebec.