@H923 if the smiley face was flashing it means it has detected a rise in oestrogen, so your body is on its way to ovulating and you can consider this a high fertility time.
When you hit the flashing smiley, you should POAS at least twice a day until you get a static smiley. This is when you should consider yourself at peak fertility.
When the static smiley happens it means LH has been detected and you should ovulate anywhere between 24-36 hours after. Bear in mind, every woman is different and every month can be different. I've had my LH surge and then ovulated 4 days later. I've also had my LH surge and ovulated same day. Keep an eye on your egg white cervical mucus and any ovulation pains/symptoms you usually get.
If you just got your flashing smiley, don't stop testing... you're not ovulating yet! Some months I had a flashing smiley for 9 days before it went static, others only 4 days. It really all depends on your body that month.
Still DTD when you can, even if you think you might have missed it this month. If you're out this month, then next, try and DTD every other day during the flashing smiley and when it goes static. Like the PP said, sperm can live inside you for a few days. I think the average is 2-5 days, depending on which source you read.