Just curious

Hi all, just a random question that came into my mind, do you always bleed a little when your egg is fertilized and attaches to the uterus? Or can it is happen and you don't know until a pregnancy test? I am curious because my husband and I have been having unprotected sex since we got married in September and I have been keeping track of my fertile days etc and so far I am not pregnant but last week we kinda did it on one of my most fertile days and I am kinda hoping yes but my period is in another week and I know to take a test it has to be after a missed period etc, just a random question lol sorry for the long post and thank you for any advice/insight in advance :-)