3 month old sudden night wakings...?

My son, who used to sleep through the night 8pm - 6am w/one feeding at 2/3am, suddenly started waking 6-7 times at night for the past week...I'm going crazy... sometimes pacifier will put him back to sleep easily, but most of the time I need to pick him up.. He seems uncomfortable, and cries like he's in pain? He might be teething since he's drooling like crazy and chewing on his fingers all day... if this is the case...how long will the night wakings last? I'm a total zombie