If I go to an Urgent Care clinic do you think they would give me a note for work

I think health comes first. If you can't work because of your health I think you need to let work know one way or the other. Obviously they will expect you to adhere to their policies and you may fail probation if your attendance is poor but if you can't you can't. It's better than trying to hide it then being fired because they consider your performance inadequate, in my opinion. Hope you recover soon. Also if you're posting on social media during absence from work and someone from work sees it, how might that affect things? Just a thought.