My boyfriend and I had sex with condom after he came. We had sex again but without protection. This time he did not cum. Can I be pregnant?

Unfortunately Yes. Remember that sperm is present in pre-ejaculatory & post-ejaculatory fluid. You should always have your partner wear a condom to prevent pregnancy, not only when he is about to ejaculate. Otherwise, you can get pregnant. Sorry.
Unprotected. It sounds unlikely, but thsi is still called unprotected intercourse. If you are trying to avoid pregancy this is still a risk, even if it is a small one.