Please help!!!!

My period is due on Thursday. Last Thursday I had light pink spotting on the toilet paper when I wiped but next time I went to the bathroom it was gone. I didn't have anything else until Sunday. I had some darker red spotting (I thought it was my period starting) but it was gone the next time I went to the bathroom. Today (Tuesday) I had light pink spotting again that was only there once. I had a BFN yesterday but now I'm super nauseous. I'm so confused. I've never had sporadic spotting like this. After the first time, I thought it was implantation bleeding but now I don't know.