If it is your first baby you will be scared whenever anything happens to him. You will visit the doctor or call the doctor for minor problems. This is not necessary. Children sometimes cry for absolutely no reason and just settle down after a while so do not worry too much about it.
Even fevers can be easily cured with the right medication. Your pediatrician will mostly give you a list of things that your child could suffer from along with a list of the medication that you can give the child without consultation.
You should visit the doctor for certain specific emergencies. If your child gets breathless or you find that he is experiencing some difficulty in breathing do not wait; rush to the doctor. If you find that your child is listless and drowsy most of the time discuss this with the doctor as it may be a cause for concern.
If your child is vomiting all the time and is not retaining too much of food or milk then do not self medicate as this could also be a case of food poisoning or dehydration which cannot be treated at home and requires medical supervision.
If your child refuses to eat then you must ask the doctor as he would conduct some tests to check if there is any internal problem. Nothing will happen to the child if he does not eat a meal or does not eat for an entire day. However skipping meals regularly is a cause of worry.
If your child has fever and it is not getting controlled with medication and is over 101 degrees then take him to the doctor as he would most likely need an antibiotic which you cannot decide on by yourself.
Some children suffer from convulsions and fits. This problem needs proper care and attention as it can harm the baby. Your doctor will give you specific guidelines on how to handle the child when he is getting fits.
Inform the doctor every time the child gets a fit or convulsion. If the child is constantly complaining of headaches it may be because there is another problem and this too must be checked. Severe headaches could also cause brain hemorrhages in some cases.