Pregnant on accident

I would be the one to get pregnant this way. We had sex and my husband wiped his cum of on a towel. I grabbed it and wiped down there not knowing it had it on there. Well I was ovulating and not taking birth control. I should of took plan b but we are happy! Talk about weird!! He must have some strong swimmers lol!!
And we have been using the pull out method 6 years with no babies!