I Have The Strong Constant Urge To Urinate Like I'm

I have the strong constant urge to urinate like I'm gonna burst but very little comes out . Last night a small light red jello colored clot came out in my urinate . Shortly After I was able to fully urinate . Today the urge is still there but not as strong . I was able to fully urinate twice but it was an effort straining . The er says there is no sign of infection and to see a urilogist but what could it be ??