By Marta Medina

This weekend I plan to join thousands of people in Chinatown in Los Angeles. We are concerned about working conditions that affect people like me who make sure Walmart's shelves are stocked.

It means a lot for me to be there Saturday. I want people to know about the hard work warehouse workers do and the intense pressure we face moving Walmart goods.

I am going to speak on stage so that people learn about what it means to work in a warehouse.

I worked in the warehouse for about five years moving Walmart products out of containers that come from Asia. I even worked through my pregnancy with my son Chris. The work is really hard and to do it while pregnant made it even harder. I thought the agency that we work for would respect the fact that I was pregnant and I would be allowed to modify my work, but they didn't care. I had to do the same work as always even though I was pregnant. A lot of times when women become pregnant they are fired so it was very difficult for me -- I needed my job to support my family, but I was also thinking about my baby and hoping that nothing would happen to him.

Walmart is particularly hard because of the high quantities and fast pace. I remember one day we had to move thousands of boxes in just a short time. That was the requirement and I had to do it even though I was pregnant.

Because of the tension I had an emergency caesarean. I had to go back to work almost immediately after my son was born, while I was still recovering, but the managers didn't care. They laughed at my concerns.

Right now I am injured. We lift heavy boxes, 50-75 pounds or more for eight hours a day. That takes a toll on your body.

This story is hard for me to recount. It makes me sad and it makes me angry, but more than anything I worry that if I don't tell people they will not know about warehouse workers. We work in huge windowless buildings in San Bernardino and Riverside. Temperatures are high, we are exposed to lots of chemicals and we don’t always get breaks or access to clean water, but with peoples’ attention and support I know we can change our jobs for the better and make sure we work in a safe environment.