Recently I heard that alcohol can decrease the effectiveness of the pill. I looked into it a little, and couldn't find anything on this? What can you tell me?

There is no evidence of alcohol consumption interfering with the absorption or effectiveness of oral contraceptives according to the latest edition of Contraceptive Technology. That said, I can't resist the opportunity to say that consumption of alcohol, especially in large amounts (more than four drinks per setting), of course, can effect judgment, memory, and cause vomiting, which certainly can effect whether the birth control pill is remembered, swallowed and stays down.