The film opens with fourteen year old Tina having sex with Ray. A few days later Tina is sitting in the car with her mother and a program comes on the radio about the number of teenagers getting pregnant. Tina's mother asks her if she knows anyone who is sexually active at her age, and Tina nods her head yes. Later in the bathroom at school, she discovers that she has started her period, and is extremely relieved. However, it only lasts two days, and came two months too late. She and her friend Laurie, a young mother, go to the doctor and discover that she is pregnant.
Tina's birthday comes, and she is saddened because another birthday has passed and she doesn't have a boyfriend. Her mother gives her a grey sweater that she desired, but is quickly angered when her mother offers advice on how to wear it. It all comes to a head when Tina tells her mother about the pregnancy. Her mother, a conservative Christian, is shocked but due to her beliefs, decides to help her daughter. Her dad is less upset and comforts his daughter. When Tina tells Ray - the baby's father - he feigns happiness.
Throughout the stressful pregnancy, Tina's younger sister Rachel reacts with both disgust and jealousy by the attention Tina receives from her concerned parents. Eventually Rachel calls their grandmother to ask permission to live with her. As the pregnancy becomes more and more overwhelming, Tina begins pregnancy classes with her mother. After hearing a story from a girl about how hard teenage motherhood is and how her boyfriend left her, Tina calls Ray and yells at him because she thinks he won't be a good father like he promised he would be. For a while she tries to make him stay with her, but when Ray isn't as present as she would like him to be, Tina goes investigating and while at the mall she finds Ray kissing another girl. She is upset and tells him she is over him and ends their relationship.
Tina is rushed to the hospital and is about to give birth when her mother has a panic attack on how her daughter is going to have a baby. When Tina is in labor, Ray shows up at the hospital with his new girlfriend only to be turned away by Tina's father, telling him "sperm doesn't entitle you to much" and tells him to wait in the waiting room. After a grueling labor, Tina gives birth to a baby boy named Caleb.