You need to talk to your lawyer that represented you in the DWI in the first place and see if the Court will modify the date you have to serve. It may be too late to have the judgment modified if it was more than 60 days ago. You might want to get a letter from your OB/GYN Dr. explaining the complications. Otherwise, you may end up having to serve the time while pregnant which would be most unpleasant in Faulkner County. If you were represented by the Public Defender's office, then go by the courthouse and talk to them to see if they will help.
This answer does not create a attorney client relationship and cannot be relied upon as a legal opinion as there are too many unknown facts to this matter to render an opinion at this time. Campbell & Grooms, PLLC http://www.campbellgrooms.com
If you are within 30 days of your sentencing and you were in district court file an appeal. If not there are several options. The judge may be able to modify the sentence or the sheriff can define the terms of your jail time. Call a qualified dwi attorney and let them help you with the process. Usually when they tell you to serve 60 days within 120 if gives you the option of weekend jail. In some jurisdictions that means you will not have to spend the night. They also will frequently give you 2 for 1 or 3 to 1 credit.