Spotting on new form of birth control

[avalina.livejournal.com]

Hey there everyone! So  I just have a quick question birth control. I just started on Microgestin, which is my third kind of Pill in the past year. I started it on time, last monday, and had no problems for the first week. Then, yesterday evening, Thursday and all through today I've had some really minor spotting. I know this is perfectly normal when starting a new type of birth control, but I've never experienced it through all my other pill starts and changes. Now on to my question! I was wondering if spotting could lower the effectiveness of the pill? I had sex with out a condom twice on tuesday and wednesday, and I just wanted to make sure I was okay, protection wise. Any thoughts?