Well yes you can get pregnant pretty much at any time. It is not safe to have sex when you have your period as a source of birth control...Thats for sure. You cant really worry about this though until your period is late next month, and you dont notice symptoms like morning sickness until well into your second month. You might notice symptoms like sore breasts and cramps, but again most woman think that its the normal period pains becuase thats pretty much what they feel like. So hang in there and dont stress until you know for sure whether your period is late.
And if it is then take a test :)