If you have been pulled over because the police officer thinks that you are driving under the influence, you want to make sure that you do everything you can to protect yourself from there claims. There are several things that you can do. 

Be Polite

One thing you can do is to be polite to the police officer. This is always a good thing to do, but if the police officer thinks that they may have a good reason to give you a significant ticket or arrest you, antagonizing them isn't going to help you in any way, shape, or form. Even if you are refusing to do anything that the officer would like you to, make sure that you are doing it as politely as possible. 

Say No

What no police officer is going to tell you is that you have the right to tell them no. You can tell them that you aren't going to do a breathalyzer test or do the field tests to see if you are drunk. You also have the right to tell them no if they ask to search your car to see if they can find any proof that you are intoxicated. If you tell them no on these things, they will generally have to wait for some kind of warrant to test you or search your car. You do run a risk of being arrested and taken into the police station or hospital for further testing, but again, you can tell them that you won't have that testing until you can have a lawyer present, and then contact an attorney that specializes in DUI cases. That will help you get the protections that you need to have. 

Offer Other Reasons

If there are other reasons that you may have problems with driving erratically, you will want to tell the police officer who pulls you over so that they can consider not ticketing or arresting you. Those reasons can include diabetes. If you are having a low blood sugar or overly high blood sugar episode, that can cause you to have issues with erratic driving. You may also be taking medication that could affect your driving. If you have problems with any of these things, you should make sure that you have some kind of medical proof that you have these issues. Generally, a doctor's note that you can keep in your car or wallet can help you with that. 

If you get pulled over for a DUI, you may want to contact a DUI lawyer who specializes in these cases that can help you fight your case.