Ask yourself the following yes or no questions:
1: Is this an extract brew?
2: Is it a tried and true recipe, or a recipe kit?
3: Did you follow the instructions fairly well?
4: Did you use all of the ingredients provided by the kit or listed in the recipe?
5: Are you fairly new to homebrewing?
If you answered yes to any of these questions, you didn't mix your wort and water thoroughly enough to get an accurate OG reading. Don't worry, fermentation will mix things up and you'll hit your FG when the yeast are done. It's pretty hard to really botch an extract recipe, it generally takes some serious tweaking to a recipe to change up the OG enough to make a difference. RDWHAHB, and all will be fine in the end.
If you answered no to all of those questions, I can't help you.