I've had a couple periods that lasted for two weeks. I don't know about drugs you're taking, but two weeks Is normal for many people. Diet, stress, and exercise also affect your hormones.
I'm 25 and am not on bc and have been on my period about 12 days now. It's not heavy but I took Plan B about a week prior to my period. What I've read says Plan B delays it, not prolongs it. I would like to know if anyone has experienced this?