birth control after babies!

Katie • ...
I've just started my birth control, I wanted to wait til after I finished breastfeeding so hubby and me used condoms. I had 2 regular cycles that were on time and only lasted 4 days! Brilliant!
Well this cycle I took my pill and I've been on ever since! I'm currently 2 weeks on my period and no signs of t going! I was fine on this birth control before having baby! Could my horomone changes be affecting it? Anyone else in this boat?