Confused

So don’t judge me because I am afraid. I have had a miscarriage before and I’m terrified of it happening again so she AF was suppose to be here on the 5th and has yet to show up I got super excited my only issue is that I’m afraid that everything me and my fiancé have been working towards is gonna be lost again. I don’t have friends who will understand and my parents think I’m too young to be thinking about babies but I’m 21 and he’s 26 and this is what I want I just don’t want to go through that grief again. So when should I take a pregnancy test and be clear of having a chemical pregnancy?