8 month old sleeping a lot all the sudden

So today my baby boy has been very clingy I don't think he has felt good all day so I have been holding him basically all day cause I can't put him down without him crying I think he is teething. He already has 6 teeth 4 top 2 bottom. He has been asleep alot today I'm a little concerned so I'm wondering if that normal for babies that are teething to sleep alot? Like he seems like he can't keep his eyes open. Also I read the teeth he has he shouldn't have at his age so what other teeth would he be getting?