Coming Off The Pill Symptoms?

I'm 17, I have recently stopped taking the pill which I was on for roughly 4 - 4.5 months. The doctors recommended I stop taking it due to irregular bleeding and extreme cramping that would cause me to black out. Since coming off the pill, 2 weeks ago, I have experienced intense headaches, back pains/pressure, bad fatigue and cramps. Could this be due to stopping the pill?
​I am sexually active, only ever with my boyfriend of 3 years. I've sex once while being OFF the pill, it was on my 27% risk day and unprotected but only three(3) days ago, I don't suspect pregnancy, even if it was, not symptoms this soon...