thanks for your query
these symptoms you have may be because of tamoxifen
like--upper stomach pain, itching, dark urine, clay-colored stools, jaundice
as you tell that you go for routine blood test
and all reports was with in normal range.please see is your hemoglobin
lebel are in normal range.if it is less than you have to go for stool occult blood test to exclude any intestinal bleed.if hb is normal then nothing to worry .