I Had A Robotic Prostatectomy In Jun. Was Fine For

I had a robotic prostatectomy in jun. Was fine for 4 weeks and then developed a debilitating pain in my left groin. Ct scan shows nothing, no hernia, etc. my urologist basically said there is nothing he can do. I am visiting my gp on Thursday. Please tell me what this could be. I can hardly walk from the pain