Its unlikely for a tablet to stay that long. However, if you are concerned, go to your ENT doctor for a check. If the tablet can be seen in any of the nasal cavities, will be taken out or else a fine flexible lubricted tube may be passed through each of the nasal cavities that will dislodge the tablet if at all its there.
If you live in the US, the Neilmed Sinus Rinse is the easiest to find and use.
Try saline irrigations/flushes. You should see your surgeon if this does not come out.
HI Sam what you can do is take a bowl of lukewarm water, dip your nose into that bowl and try to inhale water thro' the nose, initially it proves to be difficult but really works wonders. This technique we usually use after sinus surgery to clear off the thick crusts and clots. Try this.