My 3 week old has been using an SNS for the past two weeks to supplement about 5 feedings a day. The past couple of days she gets very upset at the breast w/o SNS if there isn't immediate letdown. She will barely try to suck and then pulls away screaming. As soon as I set up the SNS and let her drink from that she is fine. Is there anything I can do to get her back to just breast a bit more?