So I started taking birth control to help my periods

Did you just start taking it or have you been taking it for some time? It takes multiple months for your body to get used to it. So periods can still be a bit weird until the. You feeling sick and headache could just be a random symptoms of normal sickness sit might not be birth control related. It just depends on how long you’ve been taking it

Birth control is not a fix to “regulate periods” it’s a bandaid solution that does not work for most women/ makes periods worse or not at all and does not regulate your natural hormones. I would recommend seeing an endocrinologist. Rather than an Obgyn or a doctor.

If you missed a couple days then that’s probably why you started earlier. Some you need to take it at the same time or everyday for it to stop the periods until later