Why are my implants molding to the shape of my push up bra?

I'm just 6 months post op with cohesive silicone gel implants( textured, tear drop shape, sub muscular implant). I augmented from a size A to a C. I'm noticing that after wearing push up bras that my breasts take on the shape of the bra. There is a flat area created by the padding in the bra. After sleeping without my bra my breasts seem to regain their original shape. It has been quite uncomfortable and I'm worried that it could be displacing my implants.