Implantation bleeding or what?

I need advice! I gave birth via c section on July 3rd so a little over 7 weeks ago. I was pumping at around 4 days then around week 2 started breastfeeding then at week 6 started formula. Well a few days ago I thought my period was starting cause I went to pee and had blood in my undies. Then It turned to brown spotting and stopped a few hours later and hasn't come back.. I did have sex 6 and 10 days before that happened so I'm wondering if that sounds like implantation bleeding or if that's normal from my hormones adjusting or what y'all think.... TIA..