Could it be semen, if you are not using a condom? Or simply vaginal lubrication due to arousal response. Tricamonis will give a clear discharge but that would not be related to intercourse time.
Hi: Most likely, it is just a mixture of now-liquified remaining seminal fluid and perhaps some of your fluids. This is perfectly normal. Hope this helps!
If pelvic floor is weak, it vagina may leak fluid. to Strengthen pelvic floor a female can do kegel exercise. google kegel exercise and learn the details. If the exercise resonate with you, you may try for a month. Dr. Kegel has devised this exercise, hence its name is kegel exercise.