Teething?

I'm wondering if Patrick is teething. He feels warm and is fussy. Every time I put him down he will be okay for about five minutes and then he starts to fuss and cry. Once I pick him up he stops. He is also not eating as long as normal. Usually he nurses for about 20-25 minutes, but the last two days it has been more like 15 minutes. He has been chewing and drooling a lot recently. I'm not sure if that is teething or just being 5 months and trying to eat everything. I don't see anything trying to pop through.