Help and advice

Hey mamas my LB is 14 weeks old and has been really really off today barely finishing his bottles and turning his head away from them or putting them at the side of his mouth and chomping on the teat when I try to give them to him,and being really clingy and fussy I can’t see any signs of him being unwell and he dosent have a tempature I’m worried something is wrong? I’ve also checked his mouth for any signs of teething but I can’t really tell???? Can’t see any teeth pegs or anything? Any advice please x