It takes six weeks for you to heal after having a baby but more like 12wks for your uterus to fully retutn to normal. It coulf be your uterus recovering. But if you're worried, wait a couple of weeks and do a test.
Take a pregnancy test. Nobody here would be able to tell you if your pregnant or not. It's possible so your best bet would be to take an hpt or see your doctor. Best of luck to you