Boobs won’t empty???

I exclusively pump for my 3 week old and I noticed today that I’m having a hard time getting milk to come out as quick. I have to pump for 40-50 minutes to get the amount of milk out that normally takes 30 minutes. I just pumped again for 35 minutes and only got two ounces. I notice my boob is hard on the top and there’s a spot on the other that is hard too. I don’t know if my boobs are sore from pumping or what. I’ve tried massaging them and took a hot shower but no luck. I also got a positive covid test today. Could that make a difference???