newly diagnosed breast cancer

my question is this

i had no insurance on 3/19,  i went to my primary because i was having massive hot flashes and wasnt feeling myself.  i went in and she did a breast exam and said that she felt what she thought was a fybroid.  so she scheduled me for a mammogram.  my mammogram appoint was set for 3/29,  before this appoint i applied for insurance through a broker,  got the paperwork going. 

i went to the mammogram and they said that there was an area that was suspecious and they would like to do an ultrasound.  they did the ultrasound that same day.

i recieved my approval for insurance on apr 2.  the same day i get a call from the ultrasound to have me come in that day for a biopsy.  i went in for the biopsy and had them send the finding directly to my primary.  it took till 4/12 for the lab to have the results sent to my primary.  my insurance took affect on apr 15.  the same day my primary called me in the moring to come in so we could talk about the findings.  i was diagnosed with infilterating ductal carcinoma of my left breast.  by the biopsy was to scanty to tell what grade or what receptor it was. 

so my primary sent me to a breast specialist who sent me to do an mri.  one the mri came back it showed not only the mass in my left breast but also masses in my right breast that the first place didnt catch.    the breast specialist called me in and asked to do biopsy's on both breast again.  the next day they called and stated that i had stage 1 grade 9 invasive ductal carcinoma in the right breast and stage 2 grade 9 in the left breast.

my insurance is now saying it is a pre existig condition and they are asking me for paperwork from my primary and all other doctors i saw prior to april 15,  what do i do?    if i wasnt diagnosed until the 15th would it actually be concidered pre existing?