Awaiting Tomosynthesis after finding lump/mass

hi ladies! Trying not to overthink things, however I found a large lump in my upper right quadrant of my right breast a few weeks ago. I thought maybe it was related to my period that I had in February, so I let it play out for a couple of weeks... It has not went away. I had a breast exam done last Friday and my gynecologist also agreed but it was strange and has ordered a diagnostic mammogram. I go in on Wednesday of this week March 7th and I am hoping to get some kind of information before I leave there.

My mother was diagnosed with breast cancer when she was 45, I am only 34 in a couple of weeks however I'm a little bit nervous. I have had two children, 4 and 8, I did not breastfeed them due to other complications, I am in otherwise healthy female.

I found my lap while I was laying in bed I move my right hand up to rest it on my side and discovered a really hard spot on my upper right breast. I can feel it pretty high up and over close to underneath my right arm. I am unsure how to feel at this point trying to be as educated as possible without over stressing. I won't know anything until Wednesday so it does me no good.

The best thing I've been able to do so far is to read all of the different forums on this site, it's been incredibly helpful. Well I haven't been diagnosed and who knows what my chances are, it's humbling to read all of the stories and life changes that so many of you have had. Since it's a diagnostic mammogram I should know something when I leave there, my husband will be with me so at least I have some kind of support depending on what they say. One way or the other I'm ready to move ahead and get answers.

One question that I have is how many of you found a large lump in your upper right quadrant of your right breast and what is your story?