Is it safe to take ortho tri-cyclen lo while pregnant or breastfeeding?

Yes. If you become pregnant while taking birth control pills --occurs in about 5% of users--there is no harm to your baby. Stop them as soon as your pregnancy test is positive. While many women will maintain adequate milk production on combination pills (estrogen & progesterone), some women will notice a decline. So most of the time a Progesterone only pill is recommended.