I Have A Pocket In The Roof Of My Mouth

I have a pocket in the roof of my mouth that fills with a thick slightly yellow mucus. I have had this for about 4 days. I can not get in to my dentist till 25th. I made an appointment with an oral surgeon they can not see me till April 1st same as my primary care doctor appt. should I go to an urgent care to get this checked tonight? Please advise. Thank you