When should I test?

I am posting my may and July calendar. In May I got my bfp and and then later had a miscarriage. I got my bfp on May 11th and had a miscarriage on May 18th. Now here I am in July and have no idea when to test. I only have one tube and last month I spotted for three days and had medium flow another so idk what is up with that. Anyways any advice would be appreciated!