Irregular bleeding question?

Okay, Month before last, I missed 3 pills. I just simply forgot to take them. I took them on the fourth day when I realized I had missed them. That month, I was a day or two late for my period. But I did get it. For the entire next month, I had no . Had a regular period too. Now, this month, I'm on my second week of active pills, and yesterday I had some very light brown discharge. Just when I wiped. No cramping or anything. Now today, its pink. Is this breakthrough bleeding? I had the day before all this started, and once the day I got off my period. Which will be 2 weeks ago on saturday. Both times were w/o a condom, and my boyfriend pulled out. I know I need to be using a condom but it was a spur of the moment thing and we didn't have a condom. Can anyone explain to me what this is? I'm not trying to conceive and I don't have any pregnancy symptoms. I'm a little worried about it and just want someone to give me some info. Thanks everyone!