My 10 week old boy is the happiest, most content baby all day and night, smiling all the time, sleeping 9 hours at night with no problems. Over the last few evenings he will just randomly start hysterically crying with real tears. He is showing classic signs of teething (young I know, but it seems to be that all babies in my family teeth really early) he does eventually settle after some calpol but it's heartbreaking as it's like real pain. Does anyone else's baby do this?