Wrk in Houston, TX; 5 months pregnant. Told my atty I wanted 3 months off maternity leave. The answer no. Can they fire me?

I work for a law firm in Houston, Texas. I am 5 months pregnant. I told my attorney that I would 3 months of maternity leave. He said he would think about it. I also talked to the assistant to the owner of the firm who informed me that more than likely the firm would fire me after 6 weeks. I work for Labor & Employment firm. I was under the assumption that 3 months would be the max. Am I wrong? Can I get fired over this?