sinus infection

I had 5 teeth extracted less than a week ago, now I have a sinus infection, am taking antibiotics just wondering if this is normal?

[Jerome Tsang, DDS]

Its normal in the sense that it can be a complication from extractions but it is not necessarily an everyday occurrence with extractions.  I would recommend going back to the dentist to check it out.  They may want to repack the socket or just prescribe a nasal decongestant to allow it to heal.  They will also recommend you not to blow your nose or cause any pressure in the area.