When should I test?

So I have really irregular periods which made tracking even more stressful. I decided to take the month off and just see what happens. I never know when I ovulate because my periods are so out of wack so I can't go by a missed period. On the 11th I had pinching that felt like ovulation cramps, and I had ewcm. On the 20th I had brown blood on the toilet paper and then nothing since then. I'm hoping that was implantation. If I don't know when my period is due how long should I wait after possible implantation? Any help would be appreciated☺️