First time sex after postpartum.

Did you bleed the first time you had sex after postpartum? I had spotting for 5 weeks after C-section, then it stopped for a while, then i had periods i guess, that were way less my normal periods, stopped after 4 days, had sex the fifth day and i can see blood. Should i be bothered about it? I breastfeed and give formula to my baby girl as well. I am not on any medication or contraception.