Hi Biggswife
if you have invasive ductal then you should be covered. Phone your insurance company and they should send you a claim form. Even though they don't cover your DCIS, the invasive part should mean you are covered. Depending on your company I don't think you need anything else other than a cancer diagnosis. Just phone your company and get the process under way as it takes time for them to process it all and contact your gp for confirmation of your diagnosis etc..
Good luck. X