False negative???

Okay so I’m 8dpo and last night I felt dull period like cramps and they stopped after about 20 minutes I strongly feel like it was implantation but I don’t know, this morning I took a clear blue and it was negative I’m 8 dpo idk if it could be false and I just have to wait a few more days to test. There was no implantation bleeding or anything but I head not everyone has implantation bleeding so someone please help!!!!!