Implantation bleeding ?

I had my period last Monday so I know it’s not my period. I always have a regular period never switches up. I was with my boyfriend and he kept telling me he think he came in me but wasn’t to sure I didn’t really pay to much attention because it was two days before I started ovulation so I didn’t think I could get pregnant

( can you get pregnant if not ovulating? )

So that day I slept over then the next day was the day before ovulation and we had sex again ( unprotected)

And that night I went home. The next day when I wiped I saw this

At first I thought it was poo cause it was so dark and I actually did just finish pooping ( Tmi) so Ik this is nasty but I smelled it. It doesn’t smell like anything

But I was still like wtf cause I know how to wipe myself so ain’t no way poo is right there but okay, I wipe myself and don’t think nun of it.

Go to the bathroom again .. same thing

This morning I use the bathroom and same this except it’s kind of lighter now and I have these light cramps at like the bottom of my stomach like under my belly button and I’m scared. Im also 17 .. somebody help.