Baby chokes on milk


My baby is 8 weeks old and has a issue of choking on milk when nursing or feeding her with the bottle. Today was really bad and her lips turned purple it was so scary. I’ve tried different positions when breastfeeding her and it still happens, I hear her trying to swallow when this happens but it sounds like the milk gets stuck in her throat. We have a Dr appt tomorrow but just wondering if anyone else is dealing with this and what could be causing it?