What are the chances of getting HIV from someone if you put the tip of your tongue on a drop of the person's pre-cum (on the tip of the penis head) for about 1 second? [I am not sure if this person has HIV or not but I always jump out to the worst conclusion and I am getting worried].

In the past 6 1/2 months (since it happened) I don't think I've had any real symptoms of HIV (no headaches, dizziness, tiredness). I've been having stomach problems after I eat certain foods but I think that can be attributed to a mild case of Irritable Bowel Syndrome (because I have the symptoms of that and I have had stomach issues for years). Please respond!