Are there any steps I should be taking to protect my employment?

Just diagnosed. No other info beyond pathology report from biopsy, meeting with a doctor tomorrow, so very very early in the process. I don’t know what a treatment plan will be yet. Still in shock and am in Checklist Mode to cope probably.

Disclosed to my manager, who responded basically to take whatever time off for appts I wanted and let him know what I need. My manager is great and I take him at his word… but it’s not a small company and higher ups I don’t trust as far as I can throw.

I am in the US and my company does have to comply with FMLA.

Are there any steps I need to take ASAP to make sure I don’t get screwed? My health insurance is through my employer so I am concerned. But also, I don’t know what it is I need or will need. I’m assuming I may need significant time off at some point down the road for treatment though.

PS I posted about doctors and my diagnosis over the weekend and everyone here is so kind and lovely and I wish to thank the responders all proper but haven’t because everything else going on. Anyway thanks