I Had An Abscessed Upper Secondary Upper Molar Pulled A

I had an abscessed upper secondary upper molar pulled a couple of weeks ago. The dentist sutured the opening. I was prescribed penicillin pills which I took religiously, rinsed my mouth with saline as instructed and had the sutures removed after 5 or 6 days. It appears to me that the maxillary sinus migrated into the void and the somewhat healed gum gave way. If I push on what I think is the sinus, I can feel some pressure in the back of my right nostril. Is this critical? What if it gets punctured? It does not hurt or really bother me. How should I proceed?