I came in on friday night.. my dog jumped up as usual and then rolled on her side and urinated, with a screaching cry.

I called the vet and he said take her in, in the morning. I did, got some pain killers and they said bring her in on Monday for an xray.

well, today she is fine.. painkillers must be working, but she is walking fine too.

Should I still get the xray?

What cost am I looing at?

Has your vet asked for an urine sample to check that first as you said she urinated as well as cried out.
Might be an idea to take one anyway & discuss the current situation before you have an x-ray done.
The painkillers would probably have helped but if she is walking fine I would hesitate before having any x-rays.
Just my opinion from what you said.
Steph