Ok first of all Hun it is way too soon to tell. You need to wait a while before you even test. Even a blood test would not show up anything yet. You would need to wait at least 5 days before you even miss a period and also no sex would not feel different if you had have conceived. If anything...
That is what I have been wondering I am not sure. Hmm that is a great question. Probably it is just the sperm does not meet the egg. Sometimes it is easy and sometimes it is not so easy. It just depends on when is your time. But yeah that is a good question.