Crown feels loose. Could it be gum swelling?

accident 8 yrs ago=2 root canals (crowned)+5 partials on front teeth=experienced with veneers and how they feel. retainer cracked few mos ago,couldn't see the dentist at the time-cont'd wearing.Noticed gum swelling & felt mvmnt in 4 veneers surrounded by gums when rub tongue against back.New retainer&decreased swelling-still feel mvmnt in 1 of crowns (root canal) when rub tongue across back. sensation of mvmnt where I normally don't feel it? No mvmnt when I tap it/gently try to move, no popping.