My 1year old has been screaming/crying for the pasthr or so. He did this longer lastnight. What…

My 1year old has been screaming/crying for the pasthr or so. He did this longer lastnight. What could be causing it? Could it be his teeth that are comming in? I mean he cutting his 1 yearold molars. And has been for a while now. How long does it take? Should i take him to the dr tomorrow? Or should i call the dentist?