Welcome to HCM
We understand your concerns
I went through the description of your problem and I think there is nothing to worry. Sometimes such accidents happen in life and it is better to ignore that, not to get too much stressed about it.
Erection and pre fluid happens when we are sexually aroused or when we are anxious about it and some times due to hormonal
changes. Is your doctor a female? You must have some thought about what happened in the beginning of it itself.
Just forget it and be fresh in the next visit. Having a masturbation
or sexual intercourse within 6 hours of the next visit should help.
Hope I answered your question. Available for further query if you desire so.