Here we go
Don't bother taking readings during the fermentation. It's fermenting! Leave it alone. You REALLY shouldn't throw the hydrometer in the fermenter. If it breaks, that batch is toast. If you MUST take readings, then take out a sample. But in doing so you risk infection for no gain whatsoever.
Better yet, wait until you are racking to a secondary and take a sample then.
Better yet, don't bother at all. Ferment in primary one week, then secondary at least two. I just told you everything a hydrometer will ever tell you about whether or not the beer is finished.
If you want to know the alcohol content, take a reading on the wort and then a reading at bottling time. Why oh why do books tell you that you need a hydrometer to tell when beer is done?? It's insane!!
You did sanitize it first, right? At this point, I'd leave it in there so you don't risk infection or break it trying to get the silly thing out.
