I am 39yrs old, had mammogram 4/10/10came back normal. when should i have another mammogram? both my grandma's had breast cancer.

See details: Yearly mammograms are reasonable. Frequent self examinations are your most valuable screening test.

At age 40: Unless your grandmothers had breast cancer at an early age, you should have your next mammogram at age 40. You should have them yearly thereafter.

You can: begin annual screening at 40, so your next screening mammo should be in a year.