Should I get a lawyer for this DUI ? No Blood or Breathalyzer just a urine sample hours later?

Ok I don't know my blood alcohol level and I wasn't given a breathalyzer. I had 3 drinks at a bar at around midnight leaving at 2am and approached by police at almost 3am. I remember the event exactly and was not impaired. I was rear ended by a car then got out to discuss the matter and exchange insurance info. The guy would not give me his info he claimed I backed into him (no damage but scratches on my vehicle) The cop immediately ask me was I drinking. I said no I was upset that he could care less about the accident as well He simply arrested me and parked my car on the side of the road. I took a urine hours later at the station. While waiting I went to sleep (I did not pass out at all) I had just gotten off work and headed to dinner so I was exhausted (I have proof) They decided to take me to the hospital where I slept and was given an IV. I had no blood drawn at all (Unless they did it while I was sleep) I would have woken up so I doubt that