If you topped up the volume to five gallons (assuming it was a 5 gallon kit) and used the ingredients supplied then your OG should be very close to what the kit says.
It is possible the wort did not get mixed with the top up water and you got an inaccurate reading but in that case it usually reads low. Have you used the hydrometer before or tried it in water to see if it reads about 1.00?
If it was a kit, you followed the instructions and used all the ingredients it's likely to come out OK anyway. Tell us how things went and we can help.