Thanks for sharing your concern.
your history suggests that you are worried about the complication,faced post extraction of third molars.
Please do not get worried
The white tissue you have mentioned might or might not be the clot.
But, if you have symptoms like dull aching pain in the 3rd molar then you need to get worried.
Since, presently you have no symptoms,please do warm saline rinses after food gently and observe for two more days.
If the tooth ache
persists then you can revisit your dentist
for evaluation else no need.
Please understand this fact, that the clot which develops to protect the wound gets well stabilized within 48 hours .so there are very rare chances of dry socket
until and unless there is some forceful rinsing or biting on hard food stuff is done.
Hope it helps.