Hi and welcome to you. My goodness, I am sorry for the time that you had with your last pregnancy.
We can't provide any legal advice here as far as whether or not you should contact a lawyer, but I can tell you what I would do if in your situation. I would order all of my medical records - from the doctor's office and both hospitals - and I would find a high-risk OB to go through them with me, if anything, it will help you to understand just exactly what happened. My husband and I actually went over our records with three different perinatologists to fully understand our experience with preeclampsia. I would guess that they would be the ones qualified to let you know whether there were any legal options available to you.
Again, I am so sorry for your experience. The women here are wonderful, full of support. Please don't hesitate to let us know how we can be of help.