am i Pregnant? implantation or period? Help!

5/13/20 Ughhh okay so basically I had unprotected sex on May 2nd and my period was scheduled to come on the 8th so I don’t think I was ovulating. My cousin told me if I ingested vitamin C supplements Id get my period faster so on May 10 I took 2,500 mg of it. I’ve been cramping since May 11 but no period. On the morning of May 12 I took a pregnancy test in the morning and it came out negative. Then, later that day on the 12th I wiped after peeing and saw some blood on the toilet paper. It was sort of orangish with some red but not bright red. I thought my period had came but I was wrong. I’m spotting quite a bit but no actual period, just stained underwear and smears on toilet paper after wiping. I still have cramps. My breast are also tender and I am bloated. Do you think this might be implantation bleeding or my period about to arrive? I am so stressed and worried, I really hope I am not pregnant. Has anyone else experienced this? what happened? what do you think?? Also how long does implantation bleeding last and when should I take a pregnancy test once again?