Does anyone know what this is? Possibly tmi

So I was diagnosed with pcos June last year when my partner and I were struggling to fall pregnant. I started metformin in December last year, and haven’t had a period since November. I’ve been pretty crampy for the last couple days and have had crazy weird discharge so started wearing liners and pads thinking my period might finally be coming. Then I got some pink blood? Discharge? But the amount in the picture is it? No more ‘bleeding’. I’m still crampy but don’t know... could this be implantation bleeding? And if it is, when can I take a pregnancy test?

Thank you in advance