The penis is just a tube through which semen travels. The penis does not make women pregnant. Sperm cells do. If there was semen or precum, yes, pregnancy is possible — even if the penis was just rubbing on her leg. Ejaculate has a way of getting to places it's not wanted.
Always, always, always wear a condom unless pregnancy is the goal. And since people don't use condoms correctly 14 percent of the time, make sure there's a secondary method of birth control at work, such as pills, depo vera, etc.