Yes, they do. about two week's into tihere gestation period for about one week.
actually pit bulls don't bleed through their pregnancy but some might if they have problems or a strange condition.
Six fighting bulls, accompanied by six steers, run each morning during the 8 days of the Feria del Toro in Pamplona. The number of bulls in other bull festivals varies, depending on the fiesta.
Each morning from the 7th through the 14th of July, six fighting bulls and six steers run in the encierro during Pamplona's Fiesta de San Fermín.
The bulls are held in corrals on the edge of town. In the morning of the fight the bulls are run through the streets of Pamplona to the bullring where they are then held in small pens until their turn to fight.
See the related link. About 9 weeks.
Bulls are released during the event.
The bulls spend the first 4 years in a pasture on a ranch that is devoted to raising fighting bulls. Once they arrive at the bullring they are kept in corrals until the morning of the fight when they are moved to small pens under the bullring stands.
The bulls to be used in a bullfight at the ring in Pamplona, Spain, are kept in corrals on the edge of town. The morning of the fight the bulls are moved to the bullring in town by running them through the streets along with domestic steers. Those crazy enough to do so run in front of the bulls and try to escape a goring or trampling,
Balls
Most certainly, especially during breeding season!
The city that San Fermin is celebrated is Pamplona. During the day is the running of the bulls and what that is where they let the bulls out and run the city.