(TMI probably) Boob Issue?

Kittery16

Is this normal...?  So I have been BFing for 3 weeks now, and I recently noticed that there are little darkish pink lines around my areola.  At first I thought they were stretch marks, but they definitely look very different from the stretch marks that I got on my belly during pregnancy.  They are on both breasts, and are on the inner part (closer to my sternum... I hope that makes sense). 

Could this be from feeding LO in the same position all the time?  That's the only thing I can think of.  I have a PP visit on the 27th, so I will be asking then.  Just wondering if you ladies had any thoughts on it.  TIA!