mrs jonalyn  i  can understand as a mother you r worried about your little son. dont worry its  common cold .after four five days he will be normal.better not  go for medicines . try to give him steam inhalation with vicks  apply vicks put one drop of nasel drops in each nostrils before sleep.even nasal drops are not good  In my home country peadiatrician advised me to prepared the drops at home 

 that is boil some   1/4 th cup water adding some sea salt and allow it to cool and use this water as nasel drops    i used to do this to my sons when they  were small and it give s relief for nasel congesion and no side effects also