Sex=babies, so yes, it's possible. Having said that, it's totally normal to sometimes be late for your period, so don't panic yet, stress can also cause your period to be late. If you haven't gotten your period in a week then take an hpt using first morning urine.
Now I'm going to lecture. Always use protection, the pill and a condom are best. No form of birth control is 100%, so even with protection you could still get pregnant, but at least it will lower the odds.