But, do you think it is possible?

I personally know a incident when a girl got pregnant without penetration but I don't know any details. But I'm sure there were definitely no penetration.
I had "sex" with my girlfriend last month. No penetration! There was a barrier i.e. her underwear. I ejaculated outside her underwear and she is now 2 days late for her next menses. I am not sure if she is pregnant!!

I'm not specialist but I think there won't be pregnancy if semen didn't go on underwear. 2 days is nothing.