My little man's not eating!?

I know i'm probably stressing for no reason but my 6 and a half month old son Jack hasnt eaten properly in the last two days. Yesterday he had cereal, a little bit of his lunch and hardly touched his dinner and only had one bottle and that was when he went to bed, then today he had only been up for an hour before he went back down for a sleep without a bottle and he ended up sleeping for 2 hours! and he has only had water and nothing to eat.... I have offered him a varitey of food but he just isn't interested. He is teething at the moment but that usually doesnt deter his interest from his food, he normally is a fantastic eater, any suggestions or should i just take him to see the doctor? Thanks for your help