Cramping and no sore breast

R

So I’m 8dpo and I my period is in 5 days and I don’t have sore breast which I usually do. I had mild cramping for a couple days at 5,6dpo and they stopped. I did take 2 test and they obviously came up negative at 6,7dpo. I’m peeing a lot and very fatigue. Do u think it’s implantation but a low hcg. Me and my husband are trying for baby #2