Help.with 10.week old puppy

Hi we've had our puppy for 2 weeks and he's been fine,yesterday he had a couple of stools containing blood I spoke to a.friend and she said it could be because he's due to be wormed so I did that last night and today his poops are very dark almost black with undigested carrot in we haven't registered him with a vet yet I'm worried sick

Hello!  It sounds as though there might be undigested blood in your puppy's faeces.  This is not normal and may indicate bleeding into the stomach.  If this is still going on and you have not yet seen a vet, please do so as an emergency in order to rule this out.