baby 5 days old and I pumped too much!

Lorraine
My baby girl was 5 weeks early but she is doing great. She is eating and pooping and my milk came in early. But at the hospital I was told to pump and continued to do so at home after each breast feeding session.  So she is only 5 days old but my breast are huge and so sore! Her dr told me to stop pumping or only do so for only 5 min to relieve some pressure but that amount of time isn't relieving any pressure. At one point I pumped for 20 min and it felt amazing! So my question is how do I safely stop pumping even though I've only been doing it for a short amount of time my body got used to it.