My partner penis slightly entered my inner labia for less than a second. am i at risk for hiv or pregnancy.

Life's possibilities: Many things are possible in life, so the answer to such questions is almost always YES. Thus, such a question doesn't have a helpful answer. The real question should be, "How likely is something to happen?" A fleeting encounter of "slightly entered" "for less than a second" is not likely to cause problems, but can possibly transmit chlamydia, gonorrhea, trichomonas, etc... Plan ahead and be safe.