Chances of getting pregnant?

Disclaimer: I know getting pregnant is always a possibility when having sex. I'm married and if I did get pregnant it wouldn't be the end of the world- just timing wouldn't be good.

My husband and I had sex last night using a condom. He pulled out right before he came, but the condom came off inside of me. He came outside of me but I heard pre cum can make you get pregnant, which was probably in the condom that came off in me. We got it out immediately after and I took plan b. I was also ovulating on my highest chance day.

I read though plan b doesn't work if you're over a certain weight (I think 165?) I am 180 and worried that might not have any effect. Plus I read on here it doesn't affect you if you are already ovulating.

Has anyone gotten pregnant from a situation similar to mine? Do you think the chances of being pregnant are pretty low or there's a good chance?