Painful when peeing

I had a miscarriage not a week ago and I have been having pain when peeing even before I had the miscarriage and I told my doctor and they took my urine sample and said there was no infection but now it got worse. It's so painful to pee, and sometimes I just want to cry. I don't know what else to do? Any idea what's causing it? I would have to call my doctor on Monday since the office has been closed since Thursday.