Implantation - when would a test be positive?

Sunday night when I got into bed I had some pretty bad cramping and I was about 8dpo. If it was implantation cramps, how soon would I test positive? I took a test this morning and negative. Is it too soon? AF isn’t due until 2/18 (I have a 32 days cycle) Just really praying this is my month. I had a MC in October and then a chemical in January. My son turns two this Thursday and I just want to give him a sibiling 🌈