Has anyone ever had a PAP test result come back with "ENDOMETRIAL CELLS PRESENT"?

Hi,

I'm 42.  Pre-menopausal.  Menstruate every 28 days like clockwork.  Am having no problems. Periods are normal, No irregular bleeding.  I've never been pregnant/no kids.  I had a pap test done about 1 month ago.  It was done on the last day of my period, my Dr. even commented that she saw some residual mentrual blood present.  Well, the pap test came back with a result of having picked up "endometrial cells" in the pap?  I've never had an abnormal pap before.  The Dr. wants to do an "ENDOMETRIAL BIOPSY" to check for anything wrong, etc.  I got on the internet immediately and started reading about endometrial cells in paps, etc.  Has anyone ever had a pap smear come back with endometrial cells present and you're PRE-MENOPAUSAL???  Has anyone had an endometrial biopsy done?  I'm just curious to know what I can expect when I have this procedure next Friday 11/12/10.  I'm concerned but am trying NOT to get overly upset or blow situation out of proportion.  Been there and done that with a breast biopsy about 2 years ago.  I've learned to try NOT to panic and stress myself out but I'm concerned all the same.  I don't know what the result could be a sign of.  I've not had any unusual bleeding, pain, problems, etc.  I feel fine and am just surprised of the result.  Any help or advice from anyone who's gone thru this same thing would be soooooo very helpful for me.  I'd appreciate it if you could drop me a quick line.  Thanks for your assistance/help!

-Donna