Is it a sinus infection??

 

I am in a state of confussion right now. I am usually very susceptible to sinus infections through the winter months (actually I have already experienced 2 of them this season). Within the last week I have become very congested at times and have had mild sinus pressure. I have taken sudafed which seems to work but not completely. Id say I dont feel much change for the better or worse. I am really just unsure because I dont seem to have all the same symptoms with the intensity level that I usually do. So, could it still be a sinus infection just not as extreme as it usually is? I need to know what to do so I am not sick for the holidays!!Please give any suggestions or advice. Thanks!!