Anyone experienced this? Help please!!!

My period supposed to come on 08/16. But last Saturday night I had cramping, leg pain and  pinkish spotting which is 10 days early. I thought due to more walk(shopping 😜) I have this pain. The next morning it turned out red and I had period like flow on Sunday and Monday. Again Tuesday spotting when I wiped(sorry TMI). Thinking this could be implantation bleeding, I took a clearblue preg test and it came out -ve.  I never had irregular periods and my period was always 6 days. Please somebody help!!! 😔