Unsure about my period please read

Sandra
So I had my baby in May and I've been getting a period since July. I've attached a picture of what my periods have looked like. I haven't gotten a period yet and I have taken a pregnancy test and it was neg. I don't feel like I have any real signs so I don't my I I guess i just want others opinions. The " next period starts on" date keeps changing because I have t gotten it