If you were wearing pants and underwear, no, you didn't get pregnant. But if you keep this up, you run the risk. When a boyfriend is pressing you with his naked penis, it's kind of like if you walk through a burning forest carrying a can of gasoline. You *might* make it through (maybe even more than once) but what on earth are you doing there? Unless you want to get pregnant, you have to say no to situations where if one little thing were to change in the heat of the moment, you would be at risk. It sounds like your boyfriend isn't thinking about what happens if the two of you lose control and have even closer contact. Since the main risk is on you, you can't put yourself in such a vulnerable situation. Talk to your boyfriend and tell him no more, and that condoms exist for a reason, and you mean it. Walk away if he seems like he isn't going to behave. Good luck, you take care of you here, he isn't.
No, this will not get you pregnant. Sperm will not go through clothing.
If you are becoming sexually active, you should talk to your doctor about birth control options. If that's not possible where you live, you should make sure that your boyfriend puts a condom on whenever his penis gets near your vagina.
To learn more about how you get pregnant, sex, and your body -
https://www.plannedparenthood.org/learn/teens
https://www.iwannaknow.org/