To be sure about worms you could get a poo sample checked for worms, including lungworm if you wish, without having to go via your vet.
Wormcount.com was mentioned on the forum earlier in the year and several members, ourselves included, sent samples away for testing.
We had the results e-mailed to us within a few days and find it really helpful to keep an accurate check on the efficiency of our worming procedures.
Bob.