Hello, I thought day 5 was a pretty safe time to take a chance but straight afterwards I got this feeling of change in the air. I'm now feeling nauseous all the time- a feeling I got with both other pregnancies but maybe not so early. I had v mixed feelings first but now apart from the fact that we're stony broke, I'm quite happy. I always hoped for a 3rd child one day but later, as my other baby is 9 months. I'd also hoped for a miracle solution to our financial disaters first but there you go. I know I'll now be disappointed if I'm wrong and its too early to test. I haven't told my dh yet either.
From what I know it would be unlikely but possible, depending on when you ovulate. IIRC, sperm last for about 5 days - so if you ovulate early (day 10 or 11 - the "average" woman with an "average" cycle would ovulate on day 14)) and you had some good strong sperm it's just possible that they may have held out until your egg was released.