Intense Burning

So Saturday night after intercourse I had extreme burning after using the bathroom. It continued to Sunday so I thought I better go to L&D and get checked. My friend delivered last week at 32 weeks because of a uti so I was worried. L&D sent me home after a negative urine and advised me to drink cranberry and relax for a few days. So I did. But I still have symptoms and I can’t take it anymore. I can’t stay off the toilet, it burns and I’m leaking. HELP?