It sounds like he is just hitting a stage where there is alot going on for him. I found that 14-16 months was very trying! Between getting molars and eyeteeth, and reaching new developmental milestones, there were alot of sleep disturbances. The best thing you can do is stay as consistent as possible, continue to follow his cues, and try not to start any bad habits that you will eventually have to break.
Good luck!