Tumor not shrinking

I don’t see my oncologist very often but after 4 AC rounds she says my once 6cm tumor measures 2.5cm after her exam. She says no imagining is needed. But to me, the thing feels about the same large original size. It’s maybe less protruding, a bit flatter, but it doesn’t feel half the size. The nurse said tumors can die from the inside out. I feel like I should just trust the experts, but I’m now headed to my third round of Taxol confused and worried. Any experiences to share?