Why?!!πŸ˜°πŸ˜“πŸ˜“πŸ˜“πŸ˜°πŸ˜°πŸ˜°

I been spotting for 6 days now. I been having unprotected sex, I took 4 pregnancy tests all negative ...Missed period no period symptoms either πŸ˜“ the spotting is very light. Any of you ladies have this happened? I honestly don't think it could be implantation bleeding since I've heard it only last for a couple of days ... πŸ˜“πŸ˜“πŸ˜“ what could it be I'm worried it could be something bad😰😰😰😰😰😰