Confused? And TMI

So, I’ve never really understood my cycle or how any of it works because I started a little later than I should have when I was younger (plus no one really taught me) I’ve only had my period for about 2-3 years and out of that time I was on the depo shot (birth control) for a year well I’m off of it now and I went to an OBGYN who recommended this app to help me actually start keeping up with my cycles anyways, anyways, about 3 days ago I took a test and came back positive but people in the general TTC group (hated so much on the photo with me being 18) saying that it was invalid so idk but I’m not supposed to have my period until next month and I’m not in any type of pain but last night I had to pee really bad and when I went to wipe I saw this? (Picture below) and that’s all it was.. nothing more than that and I’m not bleeding now but I’m having very light cramps with extreme fatigue and not like my normal period cramps like these are very light and don’t really hurt and idk what to think? Could it be implantation bleeding?