Why!?

I had my appointment last week About the pain and lump in left breast. They said i would have to come back for ultrasound so today I’ve got my appointment letter for weds but here’s the confusion ! It says mammogram RT but ultrasound LT
Why are they doing mammogram on the other side !?

Best to check everything at the same time, then there are no unexpected nasty surprises. I am glad I had both checked xxx

Well the lettet wasn’t right ! Can’t have a mammogram until I’m 35