After you are arrested for oui, you will usually be released on a $40 payment to the bail clerk (always carry at least $40 in your wallet for this emergency). Upon release, get to an emergency room hospital ASAP and pay for a blood test, using a non-alcoholic swab. Blood tests are reliable and admissible in evidence, even with some delay in the test. If your test is favorable, use it at your trial. If the result is harmful, you are not required to produce evidence against yourself, unless a Court specifically orders same during discovery (which I never saw occur in the last 39 years).
If you have any questions, call me. Doug Stoddart 508-243-4877