Post partum blood

Sarah🇺🇸 • Pregnant with my second baby- stay at home mother to a beautiful baby girl named Annabella 💚

So me and my boyfriend had sex the 6 week of being post partum and now I’m on my 8th week post partum) I been sore for 4 days now, went to the bathroom & there was light blood. Should I be worried or this is all normal? & why would it come after 2 weeks ....