Postpartum : Brown vaginal discharge came after having sex.

I need some clarify about this. I had sex with my partner after 42 days confinement. First time doesnt show it. But after a few times, the vaginal brown discharge came. Its already three days. I dont feel pain or anything . I am not sure about this. I delivered my child by c section. I hope this thing is normal. Please help me to give your thoughts about this! I am so scare right now bc this is my first time 😂