Steve says I should try and be pessimistic and hopefully it's just a badly timed cough! Sadly that's not who I am and I'll worry myself sick now. Worse case scenario, If this cough is caused by a secondary then I know from previous experiences (Sultan + Krizzie) that there is nothing that can be done for Mikey.
Though I'm obviously in panic mode, I agree with Steve that we should keep an eye on him for a day or two, and carry on as normal with the hope that the cough is unrelated and will clear.