I Am 48 Years Old And Had A Mass Show

I am 48 years old and had a mass show up on mammogram measuring 1.9 cm..it showed up on MLO views spot slice 21-90 degree slice 25 views..so had more mammo tests done..it still persisted on MLO views..but not on cc or cc spot compression views..so had to go for ultrasound..it said that it showed an area of slightly differing echotexture measuring 1.3 cm was identified..I have extremely dense breasts..Can you please tell me what the differing echotexture means..I'm really worried, and have to go for an MRI next..I'm really scared and not sure what to expect. My sister has breast cancer too