Sec. 13. A child is not a child in need of services under section 10 or 11 of this chapter if:
(1) a drug detected in the body of the child under section 10(1) of this chapter or the condition described in section 11(1) of this chapter was caused by a controlled substance; and
(2) during pregnancy the child's mother:
(A) possessed a valid prescription for the controlled substance; and
(B) made a good faith attempt to use the controlled substance according to the prescription instructions.