7dpo and boobs and nipples still hurting?

So normally my boobs get sore a few days before af arrives and then the soreness goes away once she shows but this time around I noticed my boobs and nipples were sore starting around ovulation and I am now 7dpo and they still are sore but when I feel them I can now feel some type of hard knot is this normal could I be pregnant? Have been trying to conceive for  a year now and this is all new symptom to me