I'm 14 & I had sex on the 9th & I ended my period on the 7th & the condom broke & he had sperm on his penis but just a little bit. I'm worried that I could be pregnant? & I'm also on a birth control pill, Ortho Tri-Cyclen Lo.

All it takes is a little bit -

Yes, you could be pregnant. Nothing is 100%.

Are you? If you take the pills as directed, probably not - and probably is the key word.