Aug 29- had non-penetrative sex where ejaculation was near vagina. it was 5 days after my fertility period was supposedly over. last period 7th august. i had my periods due on sept 4 but didn't get them yet. what are the chances of pregnancy?

The chance of pregnancy is small (because of the timing and because the sex was non-penetrative) but not zero. It would be nice if periods were always regular and predictable but they are not. If your period continues to be absent a pregnancy test in one week and a repeat in two weeks should rule out pregnancy with a very high degree of confidence.