For someone to become pregnant, there has to be sexual intercourse between penis and vagina. Sperm has to enter the vagina during intercourse, which does not seem to be your case. So in your situation, if you and your partner’s genitals were not in contact, there is no chance of you getting pregnant.
I do recommend you to use a condom next time, even if there is no penetration so you both feel more safe. I also invite you to check out some contraception methods for a more long term way of preventing pregnancy, if that is your wish. Here is a web page that could help you.

Here is a couple questions from our website explaining similar things, if you would like more reassurance :

• My boyfriend rubbed his penis against me as I was wearing my jeans. Can I get pregnant?
• I rubbed my boyfriend’s genital from outside his jeans, then he touched my butt and I saw sperm on his jeans, could that cause pregnancy?

Hope that clears it up!
Do not hesitate to write to us again if you have another question.

Camille (elle/she)