Concerned because 6mo German shorthair pointer ate second sergeants vetscription dewormer pill for medium to large dogs over 25lbs. Pill that I bought and was in a basket on kitchen counter and he jumped up to reach anything he could grab and got the package and ate the pill. I'm worried of an overdoes because I previously gave him the same pill a week ago,after I wiped off something from his but that was clearish in color and the size of a piece of rice that moved. I was surprised when I saw it because we just completely all his puppy shots, tests, and check ups for everything including worms with my vet almost a month ago and everything was good and worming tests was negative.

Your dog should be taken to the vet immediately if he has ingested an overdose of the drug. Overdose symptoms are drooling, weakness, twitching, staggering, head pressing and paralysis.

This is from the website E.How.com

Dewormer is usually very safe, if you still have the package insert it should give information about accidental overdose, if you don't have the insert you can always call the company and ask them.
The clear-ish rice like thing was probably a tape worm and needs a dewormers that you will need to pick up from your vet, the routine deworming meds will not kill them.
And over the counter dewormers are not as effective as the dewormers that you pick up at the vets' office.
One of the key things about keeping the tapeworms away is flea control.
Tapeworms are the result of an ingested flea, they are not necessarily dangerous but they are pretty gross.
It is also not that surprising that it didn't show up on a fecal exam, tapeworms rarely do.
Roundworms, hooks and whips are easily detected in fecal exams, for some reason tapes are not.

I can attest to tapeworms being really gross. My cat brought one up a while ago, yes it was a tapeworm still moving. I had nightmares about that because I had to clean it up (still moving) in a paper towel of course.