My former job didn't pay me on time which forced me to quit, what should I do?

My former job didn't pay me on time, they also had questionable selling practices. For example, when things would break, the owner of the store would super glue the items and sell them at full price! He wouldn't tell the customers that they were broken items. It took him almost 2 months to pay me. So I mustered up the courage to call the Maryland Labor Board, but was told that if my employer found out, I could be fired and at that time I couldn't afford to be fired. After awhile I got so tired of not being paid on time that I quit, now I had an interview today and I think I did pretty well, but I am afraid that when the manager calls my former place of employment they will give me a bad reference. What should I do? I didn't tell the manager about it because I heard that you are not supposed to talk badly about former jobs. Please serious answers only. I am desperate for this job. Thanks.