“Flow” problems!! any tips??

I’m currently on my third period after stopping birth control. I’m having “flow” problems, my periods have been dark in color and light in flow. Has any one experienced this or know what could be causing this?

And what I can do to kind of “reboot” them to get back to my normal flow?

Last question!! Is it still possible to get pregnant with a flow that’s not my normal?

Thank you !!