Hi, so my girlfriend just recently started taking birth control . We didn't know when exactly they would kick in but we thought they did so we had unprotected sex within the first week of her taking the pill. She started taking them on a Sunday, (the day after her period) & we had sex the Friday (5-6 days after she took the pill). Just to be sure, she took plan b. What are the likely chances of her becoming pregnant? & would the pill clash & make the plan b less effective ?