On the 16th of July, I was playing with a girl... I tried penetrating her but she was dry so it hurt. I stopped. So, she layed by her side. I also layed by my side close to her. Then from behind, I was brushing her clit with my penis and she was enjoying it. I didn't know when it slipped in; just a bit of my tip (didn't exceed the head). I did that for about 5-10 seconds till she jumped and said it hurt. The tip of my penis felt oily but no fluids on it. I urinated afterwards. I did a HIV test on the 9th of August. It was negative. Any need to worry?