Am I being paranoid

I had a baby in November. And I had sex on the 23rd I think, maybe the 24th. But the 27th I bled. I thought it was weird but I figured stuff is just weird after having a baby but my back has been hurting so bad. For the last couple days. You would think it would be too early to feel anything from it (if possible) right? And no I’m not on birth control because I’m dumb. He pulled out but I know Precum and all that.

*edit- my period stopped on the 21st also. I just forgot to edit it