What can I do if I don’t have a plan b

I’m 16 last night I met up with this guy that I’ve hooked up with once in the past. The first time we hooked up I made it very clear that condoms were a must and he respected that.

Last night I asked him who was buying the condoms and he said me, when the time came I threw the box of condoms on the “bed” (it was like blankets and stuff on the ground) it was dark and I figured he put a condom on but towards the end asked him if he was wearing a condom at all that night and he said no. He said he didn’t cum in me but I’m almost 100% sure he did.

I’m 16 and definitely don’t want a kid right now. What do I do from this point forward to not get pregnant? I don’t have a plan b and I have no idea what to do. I’ve only ever used a condom.