Is it the pill or is it me?

I finished my period on the 26th Sept and today I was spotting brown/dark brown when I wiped then that was it. My pill packet finished on the 19th of Sept and period arrived on the 22nd of Sept. I did have sex on the 19th of Sept without protection, so no pills til the 27th. Also had sex the 27th. Fertile period started the 28th. I don't think I should be worried but the past couple days I have been extremely tired, dull headache and dull cramps this morning. May I add I have been on this pill for over a year. Starting to think it needs to be changed.