I am getting pink to brown spots after taking morning after pill. Is it implantation bleed?

Hello doctor,

About a week ago I had unprotected sex with my boyfriend, a day after that I took the morning after pill because he did ejaculate inside of me. I was ovulating during that time so I don't know if that could speed up the process since I took the pill about 14 hours after having the unprotected sex. Later on that day my body just did not feel right. There is tingling feeling in my belly and used the restroom a lot. I do not have an appetite because nothing seemed good to me.

On the 4th day after I started getting cramps that felt like PMS cramps and when I want to go check it was only a white discharge. That lasted till yesterday the 6th day. I was still having cramps and before I left somewhere, I put a tampon in and when I am back home I took the tampon out to see if I started my periods and it was a streak of pink and brown. I put a panty liner on just incase, I kept it on all night and when I went to the restroom nothing was on it, but when I wiped it was pinkish red color. It was not like my heavy period flow just a little then it would stop and it lightens changing to a light brown color. My boobs are tender, and I am feeling nausea, constipation, gas, and a little bit of pain but not period pains. Are there chances for me to be pregnant? Is this implantation bleeding? My period has always been regular and heavy, never light or no bleeding.