Implantation bleeding? When to test

I am 8 dpo. I had done a day 21 blood test and ovulation was confirmed by my GP nurse. My last cycles were 31 days, 37 days, 29 days, 38 days and lastly it was 45 days due to stress. So it is very unlikely for me to have period bleeding on 28th day (though not impossible). Today I got a spotting and I immediately knew. I had very faint pink blood hoping as I wiped and I saw it also dripped to toilet. In an hour or so it started to be a bit more but very light pink as described. When I have period spotting, its always very dark brown, never pink so I can tell this type of bleeding never happened. 5-6dpo I had nausea and diarrhea over 3 days. I see this is sometimes symptom as well. I was using antibiotics for my tooth so thought it caused it. I’ve heen having on and off headaches too and I don’t have them that often. I feel like i have cramping too but that might be psychological now. This only happened today. If I am pregnant and if i use a clear blue ultra early test, would i find out tomorrow 9 days dpo or should i wait?