Any individual and group health insurance policy providing coverage on an expense incurred basis or any individual and group service or indemnity type contract issued by a nonprofit corporation or the TennCare program that provides coverage for pregnancy and/or maternity benefits may not be cancelled or terminated due to pregnancy of an enrollee in the plan. If and only if a person or the person's spouse is pregnant at the time the health insurance coverage is initially purchased, then at the time of the purchase, pregnancy and/or maternity benefits for the current pregnancy may be denied as a preexisting condition. This section shall apply to any person who should have been entitled to coverage for the benefits on or after January 1, 1996.