there are chances.. any time during your cycle u have unprotected sex u have chances of conceiving.. so i would suggest wait or your next period and go for a test if u are late for it..
Any time you have unprotected sex you could be pregnant. If you are having a blood like discharge then that can be spotting so yes you may be pregnant.
There is a possibility. You should take a test. As long as the period you did get wasn't heavy and bright red like a "normal period", your chance are there for pregnancy.