I have a period question...?

So I was supposed to start my period this week and it's been different than it normally is. Usually I am very regular and it lasts from 4-5 days. Yesterday I woke up and was bleeding so I figured my period had start and threw on a pad not thinking much of it. A few hours later when I had gone to the bathroom again I noticed that I had only a little spotting and that I wasn't bleeding anymore. Today all I have is this brownish discharge and no bleeding. I started on the pill 3 months ago for the first time and my last 2 periods were normal. I have sex a few times a week with my boyfriend and we just use the pull out method. So I was just wondering, would this have anything to do with the fact that I have started using the pill, even though my last two periods were normal? I'm just worried that there might be something wrong because I've never had this happen before.