Tmi question but I have nexplanon. I've had it for 4 years(got a new one in last year) I just…

Tmi question but I have nexplanon. I've had it for 4 years(got a new one in last year) I just finished my period on the 27th. Well my fiancee and I had intercourse all weekend(we never use condoms because I have the nexplanon) today I have a dark brown discharge like dark brown and quite a bit. Any ideas?