It was about a month ago, me and my boyfriend sleep together but we did not have sex. Both of us are so scared that we just lay beside each other. we are not facing each other. But then, he finally turn to me(behind me) and become closer. Both of us had our clothes on. Then he rubbed his penis to my butt with our clothes on. he rubbed it up and down with no excitement or whatsoever. I did not feel anything with it and about several minutes he stop and turn aroun and go to sleep. It was my fifth day of period but I had finished period one day earlier. But I am still wearing pad that night in case of anything. The next day, I went to the toilet and I felt something sticky on the skin(near vagina) around the area of my pad. Could it be my discharge or his precum? could that cause me pregnant?