The last few times LO has eaten her latch has been very poor (on again off again very loose feeling latch) and now she has started clamping her jaw down on me and gnawing. I already use a nipple shield but it still hurts. I have said firm "no" and "that hurts mommy" and removed her but obviously that doesn't work and once she is put back on she just does it again. We've had so many BFing problems Please help!