It sounds like you have a plugged duct! After you pump, is there one specific area that is hard, or full? Is it one or both breasts? Do you have a hand pump? If so, take it into the shower with you, and take a real warm shower. If that doesnt' work, try a heating pad on the affected area, then try pumping after that. And if nothing else, try some Lecithin. It does work. I had a real stubborn blockage, more than 24 hours. I took a Lecithin, and it was resolved 2 hours later. Try to fix it as soon as possible. If it is blocked too long, it can develop in mastitis.
Email me, if you have questions.
wastelands@comcast.net