Hi. After My Annual Mammogram Last Thursday, I Received A

Hi. After my annual mammogram last Thursday, I received a call today advising me I need to come in for a clinical follow-up one on of my breasts. I haven't had this happen before. I am 53 yrs old. There is no history of breast cancer in my family (yet?). They can't take me until Dec. 9. You may not be able to answer this, but I am wondering about statistics on there being cause for worry as opposed to not (i.e., chances of cancer vs. a shadow). Thank you, Kathy