My 21 week old had his 3rd set of injections yesterday morning, he has never been affected by them before. Last night I had to go into him when he had gone down in his cot because he was sobbing his little heart out, then he woke up screaming his head off at about 6am, both of which are unusual for him as he is a really good sleeper. He was really bunged up this morning and I think he is teething. How do I know which one of these it is and which one to treat? Has anyone else had experiences like this after injections?