unlawful firing in texas

Hello everyone, I'm writing this to simply ask for an opinion. I'm not sure if the information I'm about to share is worth a sue. I started working at a chiro office as an assistant on sept 16. This clinic was self owned by the doctor during the interview she told me she didn't offer health insurance but on her indeed job post she had it as (insurance provided if needed) false ad. I stayed past my scheduled time on my first day which was 8am-7pm I stayed till 7:10pm and this office doesn't have a clock in and out system they manually put in the hours on a spreadsheet every day. I noticed my time was as 8am-7:00pm the following day and i asked the doctor if she doesn't pay overtime. She told me no she doesn't pay her employees for overtime. After work that day I received a message stating that that day was my last day with no explanation. I had to ask them multiple times to send me the official letter of termination because she did mention she was going to explain why on that email. They basically stated that i was fired because i was no longer needed. I only worked with them for two days. She doesn't pay her employees the extra time they stay past their scheduled shift regardless if its 30-40 minutes extra. As soon as i brought that question upon her she decided to fire me that same day. Thoughts?