You have to submit to any test allowed by the law in your state. The police can require you to blow in the breath test, submit to a blood test, and give a urine sample if your state law allows all 3 tests. Normally, if a breath test shows no alcohol, the police will require a blood and/or urine test to look for drugs in your system. Refusing any test can be met with long driver license suspensions and even a search warrant to take a blood sample by force.