Can you please tell me if it's neccesary to have a mammogram at 30?

No: Mayce: the recommendation for mammography is to begin at 40 and have one every year thereafter. There are special circumstances where mammography can/should be done earlier such as a very strong family history of premenopausal breast cancer, there is a problem (lump, discharge, dimpling, etc). If younger than 30 with a problem, a sonogram is usually done before a mammogram.

No: The American Cancer Society and American College of Radiology, among others, recommend annual screening starting at age 40. If you are a BRCA carrier or are otherwise at significiantly increased risk, screening may begin earlier.