pancreatic cyst

Hello, I am an anxious 31 yr old female looking for some answers concerning a pancreatic mass that was recently found.  I had a hysterectomy in June and came down with a fever after discharge.  I had a CT to look for a possible abscess from surgery (none were seen) but I was admitted for observation and also a pancreatic mass was found on my CT.  It measured 3cm x 3.6cm.  We followed up with a general surgeon that specialized in pancreatic surgery.  He said he was able to tell that it is in the tail and is fluid filled.  We were sent to a GI doc and had a EUP done with the intent to do a biopsy.  I woke up from procedure to find that he was unable to find the cyst to biopsy.  I then was followed up with a MRI and MRCP.  The mass is still there in the tail and I now am scheduled for a CT guided biopsy in a few days.  I am concerned about them poking needles around in there since this Endoscopic ultrasound is supposed to be so much better than ct in viewing these.  What reason is there that he could not see it during that procedure but CT and MRI/MRCP picks it up.  Any ideas???  I am a young, frightned mother of 4 that was blind sighted by this a couple of weeks ago and I am just anxious to get some answers!