Pain in under side of one breast???

[Squiggy]

I went through miscarriage for several weeks last month. I stopped bleeding the first week of July. But I want to know about a pain in the under side of one breast. Is this something that can occur from pregnancy/miscarriage? It is the right bottom side of the right breast. It actually feels like it is more the muscle/body than the tissue of the breast, but I'm not completely sure. The pain is unbearable at times when I try to lie on my right side at night. I thought it went away, but today I put my arms over head and felt discomfort in the same area, when I tried to feel it with my hand, it hurt.
I don't see my doctor again for another few weeks, thought I'd ask here if this is a possible symptom. I'm kind of freaking out a bit.
THank you

 

[drudai]

Does it feel like it could be a lymph node, is there any lump or feel like a cyst under the skin? Or like that "pulled muscle" feeling?