8 month old not sleeping through the night anymore!!?

My son is 8 months old. He was sleeping through the night just fine and within the last 2 1/2 months he stopped!! He wakes up about 2-3 times a night usually and sometimes giving him his pacifier will put him back to sleep but sometimes it doesn't work!! If I put him in his swing he will go back to sleep but if he lays in his bed he will just cry. People keep telling me it's because he is teething but I am feeling like maybe it's something else since it has been going on for so long now. He has not even had a tooth break gum yet. Has this happened to anyone else?? Some days I feel like he will never sleep through the night again!!