How do you know if your baby is teething ??

First time mum here.. my LG has been screaming her head off since last night… won’t settle unless being held and even then it’s not for long. Has barely slept cause keeps waking up crying. On her bottom gum I can see two teeth through it (not cut through) she’s been drooling more than normal.. blowing spit bubbles ect.. gone off her formula a little and keeps bringing her hands to her face… she will be 8 weeks old on Thursday… surely this is too early for teething.. has anyone else had this or can anyone offer advice ? thank you x