Do you really feel pregnancy symptoms right away (as in 1st missed day of your period or before)? I know everyone is different, blablabla.... but I hate it when people say I am pg, I already have symptoms and they had sex/ovulated yesterday.  This could be stress or anything.  Then they go around and tell everyone they are pg and get excited, but then they really aren't pg and are so upset/embarassed.  They don't understand why they had these symptoms.  
I have never been pregnant, but I have read a lot about it.  And I come from a catholic family where someone is pregnant at any given time (haha). I have never heard about experiencing pg symptoms between ovulation and you first missed period.
But I want to know, is it true?

Summarized question: When do early symptoms of pregnancy start?