Thanks for your query
Glad to know that you have good knowledge about immunisation.You are right if your child had received 2 doses at 6 and 10 week of age then what he needs is just a third dose which also you have taken. Now I m not sure which vaccine
he has received at 6 and 10 week, but easy five contains DTP, Hib and Hep. B. So you have to be sure about the vaccines he got in first two doses. But as far as DTP is concerned you got it in right way.
I hope this answers your query effectively.
In case you have additional questions or doubts, you can forward them to me, and I shall be glad to help you out.
Please accept my answer in case you do not have further queries.
Wishing you good health.