K.W.
Yes it is normal, but I don't recommend your method of pumping either to anyone else reading this. Both can cause lack of milk and mastitis. It is better to pump more frequently and for only 10-15 minutes.
Mastitis is caused by milk left in the breasts too long and causing an infection. You really need some relief. So go ahead and pump, take warm showers and slowly taper your breasts off so that the hormone levels that tell your breasts to make milk can go to lower levels and your breasts can stop filling up.
For a more definitive answer I really recommend you either contact your Lactation Consultant or feel free to call me for a consult @ ###-###-#### in Grapevine
K.@ The Nestingplace