Uti symptoms?

I'm 3dpo and I'm having cramping and backache on my right side along with some uti symptoms. Iv had utis before and this isn't as intense as what Iv had before. The burning is there but not the urgency to go. It does burn a bit when I go but not as painful as other utis have been. I called my dr but he's closed on weekends he did call in a prescription for me that's supposed to be safe for me if I'm pregnant but I'm just wondering if anyone else had expierence this!