Not sure when to test

Jocelyn
Hey ladies 
My fiancé have been trying to get pregnant for about a month but before we started trying we weren't exactly the safest starting on the 8th of this month I had some very light bleeding that was un like my period. My apatite has changed as well as my sleep patterns and we aren't sure when we should test because it could be too soon but I have also miscarried a few times so my fear is that I won't catch it in time 
Any ideas