If you think you have appendix problems, how long could you wait to go to the doctor?

Go immediately. If you suspect appendicitis, go to the er for eval. If it ruptures, the consequences are severe. Other problems can include ectopic pregnancy, diverticulitis and ovary torsion/twisting. Appendicitis is generally an acute problem, not a chronic one. A doctor can examine and order tests to diagnose the problem.
Why wait? Acute appendicitis progresses to rupture typically within 2-3 days after symptoms begin. Symptoms include constant, progressively-worsening right lower abdominal pain, loss of appetite, nausea+/-vomiting, fever. The sooner appendicitis is diagnosed, the easier it is to treat--nothing good happens by waiting. If you believe you may have appendicitis, the best time to go to the er is asap.