4 months ago I engaged in sexual activity with a girl who is now known to be HIV positive. However I never penetrated, and our sexual interactions were limited to my penis caressing her clitoris in a rubbing motion for, at most, a minute. There was no penile-vaginal penetration and thus no ejaculation.
A few weeks later I noticed my lymph gland at my groin was swollen, however only the left side showed signs of observable inflammation.
This left sided inflammation has no noticeable pain (or some which may be psychologically induced) and has not reduced in size until now (4 months have passed). I am now concerned as to my risk of contracting HIV.
What are the chances of HIV contraction? Also, are there any other probable causes for an inflamed lymph gland (noticeably one side) at the groin?
** Thanks in advance, a concerned first year medical student.