Here, I actually watched a video on Discovery about a shark giving birth to two baby sharks. The expert talks about how these sharks give birth differently and how they try to make the experience natural for the sharks.
Bull sharks are viviparous, which means they give birth to live young, usually 4 to 10 pups at a time. The pups are about 28 inches at birth and take about 8 to 10 years to reach full maturity where they are about 6 to 13 ft long. It takes bull sharks at least 8 years to reach sexual maturity. They usually mate in the brackish water of river mouths during the summer months and give birth about one year later. Young sharks are often found in protected bay areas where they can grow and mature into adults.