Welcome to HealthcareMagic. Pregnancy
can occur only when a sperm fuses with an ova or egg. For this the sperms need to be ejaculated inside the vagina or there should be entry of sperms inside the vagina which travel through the cervix
to reach the egg in the fallopian tube
. From the description, chances of pregnancy are less likely because in this case a mechanical barrier of cloth was present between the sperms and egg during intercourse and rubbing. So pregnancy is not possible.
Hope it helps you. Regards.