in montgomery county texas i was arrested for a first time dui.

Yes. If you have a misdemeanor or felony conviction, it could enhance your punishment for this offense. If its a class A misdemeanor (1st offense dwi over 0.15), and you have a prior felony or class A misdemeanor conviction, it raises the minimum jail sentence in the punishment range to 90 days. if its a class B misdemeanor (1st offense dwi over .08, under 0.15), and you have a prior felony or A or B misdemeanor conviction, it raises the minimum jail sentence in the punishment range to 30 days. See Texas Penal Code 12.43 Sec. 12.43. PENALTIES FOR REPEAT AND HABITUAL MISDEMEANOR OFFENDERS. (a) If it is shown on the trial of a Class A misdemeanor that the defendant has been before convicted of a Class A misdemeanor or any degree of felony, on conviction he shall be punished by: (1) a fine not to exceed $4,000; (2) confinement in jail for any term of not more than one year or less than 90 days; or (3) both such fine and confinement. (b) If it is shown on the trial of a Class B misdemeanor that the defendant has been before convicted of a Class A or Class B misdemeanor or any degree of felony, on conviction he shall be punished by: (1) a fine not to exceed $2,000; (2) confinement in jail for any term of not more than 180 days or less than 30 days; or (3) both such fine and confinement.