ADH almost 3 years ago and now a 4mm "something"

I went in recently AFTER a "normal" mammogram that can barely be seen due to extremely dense tissue (I am 53 and postmenopausal.) Yes, I can Google (yikes) but my report says this "mass" is "circumscribed, oval, hypoechoic 4 mm" in the breast that had the ADH. (No Doppler or posterior features.) Benign-appearing microcalcifications are seen, too, and not reported as being seen before. This mass was NOT seen on my mammo, but on the U/S only. The rad wants a recheck U/S in 6 months. I did call my BS and she agreed that would be fine.

The images show a weird little not so oval thing, more like a weird little square or something. I've never had something come back hypoechoic before (that they wanted a recheck on). Anyone else like this and it wasn't benign? (Just curious. I've had many years of "stuff" going on so when they say lump I'm kind of desensitized to it, but this one looks different from anything I have had before (like my fibro change, adenomas, cysts, etc...) Not sure if Ultrasound images are allowed to be posted...)