My 2 year 8 months old son. Had  fever with cough which lasted for a week.. for which he was prescribed p250 and levolin. Now though the cough  has gone... He gets mild fever only during night.. which last for about 5 hrs .. . after this fever episode, he has lost weight and looks weak in general. He take normal food but show less appetite.. Should he take any blood test. Concerned as He was vaccinated up to 1 year only..