high hydrometer reading

I bottled my second batch of homebrew a week ago and I can't stop thinking about my hydrometer reading when I bottled it. I did a Brewers Best Oktoberfest kit and hit the O.G right on at 1.056 and when I bottled my reading was supposed to be around 1.016 and I ended up at 1.02. The 1.02 reading stayed steady for just over weeks so I figured it was done fermenting. It fermented in the primary at 68 degrees for two weeks then 64 degrees in the secondary for two more weeks. My question is this,
1) Should I expect bottle bombs? and
2) Is the difference in hydrometer readings (1.02 vs. 1.016) a hudge difference? and last but I'm sure not least
3) do you think fermentation was stuck?
Thanks and I apologize if this seem like a total noob question

I take it you mean 1.020?

You'll be fine if it stayed at the gravity for more than 3 days. I've bottled quite a few extract batches at 1.020 with no issues.

Besides being 4 points off is not a bad thing.

thanks for the speedy response. I should once again be able to sleep