I dont mean to laff at your expense...I just remember that stage. You will "get your steps in!"
Sorry also I said "trust your vet" before...

14 days seems way too long.
Cant recall the dose or the exact med but we cut it in half at four days and stopped altogether at 6, with vet ok once it looked like it was healing and Bonnie wasnt picking at it, cone off.
Those stitches look ok to me, and if he is not chewing at them he probably doesnt need the meds either, imho.
But I'm not a vet, so get a second opinion. It cant hurt and you may need a second dobe experienced opinion in future, if you are getting uncomfortable with current one...
Since you have had dobes before, I'd say trust your gut if this vet is not as well versed/communicating as others you trusted before. I dont like the head tremor...IHTS is another "above average" condition in the breed and the causes are murky, one trigger may be meds...
I think there are fewer vets coming up in this breed, if the trends in vet practice to franchises in small animal generic chains, and referrals to high dollar Emergency Clinics are continuing.
And as the slow decline in dobe breed club show chapters and working trials, "appear to be trending", anecdotally.
So its worth finding that backup...early.
For anyone lurking here thinking about the breed...good to do your homework on this: "find dobe experienced vet!"
Before you get in new puppy sleepless phase...
"These aren't easy or cheap keepers" - Bug