that amount of time is often just fine - but the low number would tell us if you ended up with too much fermentable sugar left, lending to the possibilities of bottle bombs.
If you don't have a hydrometer, get one. If you have one, use it. Record the numbers with a sample of pre-fermented wort (starting gravity) and finished beer, prior to bottling (final gravity). The numbers will be something like 1.045 (sg) and 1.010 (fg). If your fg were 1.025, we would caution you about bottle bombs.
Once in a while, the yeast just poop out and you have a stuck fermentation. If they rouse up again in the bottle - you could have problems. Better to diagnose before you bottle. So if your fg was 1.025, we might have advised you to pitch another packet of yeast and warm up the beer a touch (70F, maybe), or even pitch a packet of champagne yeast to drive that number lower.
good luck with this one - ! Hope it all works out.