My vet never held one, but there's so many pups and dogs around where I live that there's always some socialisation. Today my 14 month old dog met a 12 week staffie pup (his first ever staffie friend!). The owners had no idea what to expect in terms of what was play and what was appropriate, so hopefully I helped them a bit, as my old pup played with their young pup. I'd suggest trying to introduce your puppy to some older puppies (maybe from 3 months-2 years old), so they can learn how to play with dogs that have already been-there-done-that recently.
I'm sure your pup will be fine - the first few experiences they have are all new to them and you, remember, so they - and you - don't know what to expect. Keep on with the socialisation, but not just with tiny pups - the older ones definitely teach them how to behave!