My question involves labor and employment law for the state of: Nebraska

Part time worker as an Ultra Sound Tech and being force to only be on call/as needed. No longer having hours Part time because they stated "we have the other tech now". I'm pregnant and due in a few months, the company had hired a full time worker for another department but also has Cert for Ultra Sound. They said they would use her to cover my maternity leave which was obviously not the case.

They obviously have moved me to "PRN" to avoid me being able to claim unemployment and from technically firing me. Can I still claim unemployment because now I do not have guaranteed hours? Also can I request from my employer a letter requesting reason for being removed from part time? Is this a possible case for unfair dismissal?

Thank you for your time.