RIF and pregnancy discrimination is this right?

In February of this year the job that I was hired for went down and was “supposedly” going to start back up in April of 2020. I asked my manager if I could take an voluntary layoff (I had just found out I was pregnant) he told me if I did I wouldn’t receive UI benefits because they could offer me other work which I accepted. July I was moved to a different department which required constant lifting and bending my supervisor emailed HR manager stating that I would sit down when line was down I explained to her that I was in my 2nd trimester of pregnancy and was having pains in my back. She told me I needed to get an excuse from my Dr and fax it over which I did, she then call my Dr office talked with a nurse and told the nurse she could not accommodate my Dr request. I then inquired about opening a charge with the EEOC because she had accommodated several other employees in the same situation. I then spoke with my Dr who was willing to change how many hours he recommended me to work. After being off of work for 3 days because HR was still “trying” to find somewhere to place me, I returned to work on a regular job lifting more than 20 pounds(despite my Dr request) but I never complained or said anything. Fast forward to August I was called into HR where I was handed a severance package, separation notice stating RIF. Myself and 9 other employees received package with myself and 2 other employees being on light duty and 1 of the other 2 also being pregnant on FMLA. I really feel like the company is discriminating because of my pregnancy. Even though I was placed on light duty I was assigned to a regular job doing all the same duties as my other coworkers(we would rotate jobs every hour) and I never complained. What makes me think it was discrimination is after I received my severance package for RIF the company STILL has 3 temporary employees on the same job that I was doing and I was a full time employee. I would just like to know if this sounds like discrimination or should I just sign severance package.