Take a test, if its negative wait a few more days and take another. If still no period, go to you Doctor.
Remember to always use a condom to stop the transmission of STD's as well as pregnancy. STD's can be transmitted without your partner ejaculation inside you.
LOOK AFTER YOUR BODY AND IT WILL LOOK AFTER YOU.
neither. sometimes after you have sex, your vaginal tissues rip, especially if it's your first time. This happened to my friend, you are completely fine, but getting it checked out wouldn't hurt either. my friend just used pantyliners to solve the problem. but next time, MAKE SURE YOU USE A CONDOM. I still completely recommend talking with your doctor, but i guarantee you aren't pregnant.