Period or no period??? TMI

Neña

So on Sunday I’ll be 2 months postpartum. Just yesterday I’ve noticed when I went pee like this brownish discharge. And then again today when I went pee I saw a big clot of brown discharge. Is this normal..? I did have sex like 2 weeks ago. But i am on Nexplanon. So I don’t understand what this could be . Sorry for the pic