Thanks for your query.Based on the facts that you have posted it appears that you have undergone a surgery of
Colpo Suspension to elevate your Bladder neck for Stress Incontinence
of Urine.by using a strip of Fascia Lata as a sling. Now you have collection of serous fluid at the site of surgery over thigh.
Once in a while It is not uncommon to have collection of serous fluid in a subcutaneous plane at the site of surgery. It has to be drained frequently to avoid being getting infected Take some antibiotics as per advice of a surgeon who has performed the surgery.Do not worry it is bound to get cured ..