It is possible that she might be pregnant due to her late period. On the other hand, she might not be pregnant since late period has other causes like stress and diet changes among other things. It is safe to go for a pregnancy test to confirm.
Uhhh, if the condom didn't break I'm not sure how she could be pregnant, unless some of the sperm some how got in. But periods come late sometimes, wait a few more days and if she hasn't gotten it, make her take a pregnancy test.
Lots of things can cause her being late I agree with that but yes go to dollar store ask for the dollar pregnancy test they work just as good and you can get a couple do it first thing in the am then you will have piece if mind