A pregnant 21-year-old woman who is serving 13 years for the importation of heroin and cocaine was given an extra 40 days in prison yesterday.

In Magistrates' Court Zephyra Gibbons, of Hillview Road, Warwick, was sentenced to the additional 40 days for speeding at 62 kilometres per hour in October last year - prior to her drug conviction.

Acting Senior Magistrate Carlisle Greaves at first imposed a $235 fine on Gibbons when she appeared in court yesterday.

However, he then changed the penalty to time, when he was informed that she would not be able to pay because she was already incarcerated.

The time is to run concurrent with her original sentence.