You should use spermicides during every act of sex, whether or not you are having your period. Spermicides do not cause cancer. In fact, they can help protect against cancer of the cervix. Research indicates that if you use spermicides when you are pregnant, spermicides do not cause birth defects in your baby. Most spermicides can be purchased at drugstores and supermarkets.
Store spermicides in a cool dark place.
If they are in a warm place, they can dissolve. Cost varies depending on the specific type of spermicide used. Spermicides can be used while breastfeeding. If you do not think you can use this method during every act of sex, then you should find another method. Also, if you are very worried about becoming pregnant, then you should know that spermicide alone is only somewhat effective.