My doctor put me on bed rest, but Lincoln Financial said "nope, you can work"???

Lincoln Financial is a joke. I have been paying for short/long term disability for the last 3 years. My OB doctor put me on bed-rest at 22 weeks due to premature contractions. I have had 6 miscarriages and my son was delivered premature. I am starting to experience severe vertigo and constant headaches. Lincoln Financial denied my claim as well. I am the sole provider, now 7 months pregnant with a 2.5y old to feed. They continue to drag their feet and do not return calls. I call twice a day. I have not received my denial letter but rather a verbal by phone. I know a RN reviewed my case… How is it possible for my doctor to put me on bed-rest to prevent further complications with my pregnancy, yet a RN can say “Nope, you can work.”?