Can someone tell me what this is

Hey guys, so I recently just had the nexplanon inserted 4 weeks ago. I had it inserted like 6 days before my expected period and my OBGYN told me that my period might come but not to expect it due to the hormone changes from the implant.

Fast forward, I experienced spotting or light flow today and I expected it was normal and I was using the bathroom when i saw this. And I never seen this before and it freaked me out. Can someone tell me what this, l'm trying to figure out if it's due to the implant.