Birth control question

So I been taking birth control pills I stopped taking them last month because they would give me bad headaches and make me feel super nauseous could me stopping the pills be a result why my period is 2 days late mind u it’s never on time since I started taking the pills it’s always on different dates but my glow app has been estimating them good so far but this period I’m late 2 days could the pills be a result of it even if I stopped taking the pills how long dose it take for my body to go back to how it was before the pills anyone know ?