Why all the whinging and crying???

In the last 4 days my 15 wk old has been crying and whinging alot more than usual. Anywhere between 19.30 and 22.00 he has started to cry. Its starts usually after his 19.00 bottle. It gradually escalates from whinging into full on hard crying that can last on and off for about 2 hours. He will eventually fall asleep from exhaustionn Then he'll wake, take his last bottle and go down for the night. He sleeps straight throught thed night usually waking at 7.30-8am. Some days he in really good form til it gets to about 7.30 an evening and he starts the whinging come bout 19.30. Other days like yesterday he whinges and cries all day when he not asleep or being fed. I bought him a baby swing 3 days ago but he doesnt seem to like it. He doesnt like to be in his bouncer. I lay him on the floor to kick around and he will stay for 15 mins max then the whinging starts again. Its really starting to get me down. Hes had colic since 3 wks old but never like this. Could he be hungry or teething?