Switching health insurance at 30 weeks pregnant

Husband and I are moving to OH from out of state next month for his new job. I will be 30 weeks pregnant with twins at that point and could go into labor at any time. I need to find a doctor and choose which hospital to deliver at as soon as possible. I will at the very least need weekly appointments. We know the name of the health insurance at his new company, but when I call doctors’ offices they say they aren’t sure if they accept that insurance. When he reached out to ask his new company’s HR about the health insurance details and how to find providers, they said that information will not be available until after he starts his job and enrolls (we will be able to be covered starting his first day of employment). Is there any way I can find out if a provider is in network without knowing the group or policy number? We can probably do COBRA with current insurance- but I’m guessing that would be prohibitively expensive. And if I do that will I have to wait to get on his insurance for a year/until open enrollment at his company? Or is birth a qualifying life event for me as well as the babies?