forewarning, this might be tmi but I have an important question. I had my first actual period after…

forewarning, this might be tmi but I have an important question. I had my first actual period after giving birth finally, 2 1/2 months after, and when I went to go to the bathroom and change my pad there was something on it that worried me. I won't post the picture here it'll be in the comments, but someone please tell me. idk what it is and it kinda worried me. we thought we might have oopsed and hot pregnant again but any test we took came up negative and then I started my period. :/