Brief Answer:
This could be a UTI or 
genital infection.
Detailed Answer:
Hi,
Thanks for consulting us.
There are a  few tests that I think can help diagnose this problem. I am sure you must have had them before, but, for the current problem, you need a fresh report.
Have a Urine DR. This will rule out any UTI ( specially asymptomatic). A UTI can lead to 
incontinence, so, this must be ruled out.
Have a high vaginal & urethral swab test to rule out any ongoing infection, which can then be treated by a specific antibiotic treatment to ease your trouble.
Have a pelvic 
ultrasound, both pre-void & post-void, to exclude any 
urinary retention. This may also lead to incontinence.
Once you get some lab evidence of your symptoms, doctors can suggest you relevant treatment. 
Alternatively, you may visit a Gynecologist & have a local examination. The doctor may demonstrate your symptoms objectively by performing a 
cough test on you.
Hope I have given you some helpful suggestions.
Please write back if you want to discuss this further.
Best regards.