"Since that's the case, you used the right amount of LITERS of water for your recipe, you OG was actually what it is supposed to be for your extract batch NOT the reading you got."
Curious, then why add sugar to wort? I just did another brew today... got a reading of 1.038 (that reading is with added corn sugar) ... though I didn't stir the wort for 5 minutes, perhaps a minute or two hope every is okay
Did your recipe call for adding corn sugar now? That's odd, if a kit calls for sugar added to it, it is usually just table sugar not corn...corn sugar is usually added at bottling time.
As to why kits say to add sugar, it's to boost the ABV WITHOUT adding more body to the beer.....Sugar ferments nearly 100%, so it dries out the beer. AND if the recipe called for sugar added to it, their instructions would have given you the OG for the beer WITH the addition of the sugar.
You can always use an online calculator such as
http://beercalculus.hopville.com/recipe to figure out the og of the beer...Just look at the weight listed on the can as the amount of Liguid Malt Extract (LME) in your recipe, and also the pounds of sugar you added, that along with the amount batch size will tell you what the OG of your batch is.....like I said, even if you only mixed for a minute, your wort and water will integrate fine during fermentation, it just won't give you an accurate OG reading (The final grav will be accurate btw).
Just go by what your recipe said it is supposed to be...
If I wasn't clear before,
as long as you ended up with the correct final batch volume of the beer your recipe's gravity will be exactly what it says it will be REGARDLESS of YOUR OG reading. You are NOT converting any grain to extract yourself, the maltser who made the kit took care of that for you, so whatever they say your beer is supposed to be, it IS as long as you dilluted it to the correct volume.
Original Gravity readings for recipes are only altered in Partial Mash and all grain brewing because we as the brewer convert starches in grain to sugar (wort) and there are a TON of variables which come into play in that case and may affect our original gravity.....but in your case not....
You are fine.