When to test?

So I got my period late,and it was lighter than normal with horrendous cramps.lasted for 4 days.took a test when I was late,it was negetive. 19 days later I had my period again,same symptoms,same length.had ovulation pains on Saturday and Sunday,which I normally dnt have,since I dnt ovulate normally,which would be cycle day 6 if I really had gotten my period again.when should I test again to see if I'm pregnant? I'm so sick of negetive tests