first period

I've had my first period but im not due on now for another 2weeks yet have had some light bleeding today. There is a small chance i maybe/could of been pregnant and im not sure if this is normal after giving birth or if it could possibilly be me having a miscarriage,i've had one before it wasnt like this though but i was about 8weeks along then so thought that could be the difference as i wouldnt be that far along if i was pregnant.Im also gettin really painful stomach cramps and i've never got period pains before

sorry if this is abit confusing