It depends entirely upon when you ovulate (and you can only confirm that after it happens). It doesn't really matter if a calender says you should be fertile, what's more relevant is actual evidence of fertility. If cervical mucus was present at the time of intercourse, sperm cells can live in your body for up to 5 days waiting for ovulation to occur. So as long as you ovulate within the next 5 or so days, there's a possibility of conception. If there was no cervical mucus at the time of intercourse, sperm can only live about 30 minutes in your body.
You are also potentially fertile for 3 days after confirming ovulation. That's because of the possibility of double ovulation and the lifespan of each egg. An egg lives about 24 hours if not fertilized. If a second ova is released, it will happen within 24 hours of the first one...then can live up to 24 hours as well. Even if there is no cervical mucus is present during this time, conception is possible if intercourse occurs during this time.
Hope that helps a bit. The only real way to know whether you are actually fertile or not is to track the signs your body gives you. Evidence of fertility is more reliable than predictions of fertility.