If you used a total of 5 gallons of water, that would explain why your OG is so low. What I mean is that grains will absorb some of the water, and then about a gallon will boil off in an hour. So, you may have lost about 1.25-1.5 gallons out of that 5 gallons.
Do you have your carboy marked to the five gallon line? That's the best way to see how much liquid you end up with, and then just top up with water to the 5 gallon line.
I start with 9 gallons of water for a 5.5 gallon batch, just as an example. I use more grain, since I don't use extract, so I lose a gallon of water right there, but I also boil off nearly 2 gallons per hour.