Me and my boyfriend were dry humping he was in his underwear only and my cloths were off he ejaculate in his underwear which was soaked by ejaculation and touches my vagina can this cause pregnency ,can sperm pass through fabric and cause pregnency?

Pregnancy is not possible in above circumstances, fabric acts as mechanical protection. Contraception remains otherwise key in avoiding undesired pregnancy and associated anxiety and when intercourse is likely to occur.

Agree with Dr. P. Pregnancy is highly unlikely from what you described but you are putting yourself at risk. Use contraception all the time every time. You are exposing yourself to not only pregnancy but STDs as well. Safe sex: https://www.hopkinsmedicine.org/health/wellness-and-prevention/safer-sex-guidelines