6 month sleep regression ???

my son is about 6 months & 6 days. a little over a week ago he started waking up a WHOLE lot at night & being awfully fussy. he whines a lot during the night & cries for reasons i can’t figure out. he has always been an amazing sleeper during the night. as a newborn he only woke up to eat, as he got older he only would wake up once sometimes never. i can’t seem to figure out if he is having sleep regression or if he is teething? he has been drooling for months but since we got him an amber necklace he hasn’t that much. he puts his hands in his mouth a lot now recently but i can’t feel anything when i rub my fingers on his gums. he acts totally fine during the day & takes naps fine. i’ve tried tylenol incase he was teething & it works but only for a little amount of time . i hope this isn’t teething, i just want him to go back to sleeping good through out the night!! someone help a mama out!!