When to test...... please help

Stephanie

So today is June 16, 2018 my husband and I had sex on June 6th and then June 12th- June 14th I was spotting a little bit a brownish color only when I wiped and had a little in my underwear, I had slight cramps but never got a period, today I haven’t spotted at all. I’m just wondering when should I test after spotting if I have PCOS and have low HCG levels.