I recommend that you keep a list of what your side effects are and make sure you share them with your oncologist. Check out the side effects listed on the drug manufacturer's website, or in the hand out that you should have received when you got your first dose. Usually, the drug manufacturers have you call your doctor right away for almost any of the side effects. I have experienced the yawns and snorts from the triage nurses when you call them about your side effects. It can be quite annoying.
Many of the side effects are not life threatening, but if they really impact your quality of life you do need to make sure that your oncologist knows about them right away. Sometimes there are things which can be done to help you, and there is no need to suffer in silence. Take the risk and just take their snorts and yawns --sometimes what you tell them may actually be important.
Many chemos have side effects such as losing your hair (annoying but not life threatening). However, many of the drugs DO have interactions which are very dangerous. Ask your oncologist for a list of what side effects he wants you to call him about right away. They probably include the following, but I am sure there are others I am going to forget:
tongue/throat/lips swelling: this might be an allergic reaction which could be very serious.
heart palpitations, racing or slowing heart beat, dizziness, shortness of breath.
A rash which is on your torso and upper part of your arms and legs (again, this might be sign of an allergic reaction).
The above are ones which you should probably not pass go, but go directly to the emergency room.
Others are dehydration from vomiting or diarrhea, prolonged bouts of either---usually the drug information will guide you on what they feel is important.
So...the best thing? Find out what the side effects are before, or as soon as you are taking the drugs. TALK to your doctor and have him clearly indicate when he wants you to make an emergency room trip, or to check in with him, or what he feels is a serious problem. Forewarned is forearmed. I am sure you would be happier knowing what is serious and what isn't. And better than listening to my chemo-infected blathering....it is best to get the information from the horses mouth....