Hey Relle

you may have a bit of membrane or placenta left in you uterus...the contracting of your uterus causes this discomfort as it is trying to get rid of the contents.

Your bleeding also indicates that there are still some bits of the afterbirth

if your blood loss has an offensive odour, or you are feeling rather average i would suggest you pop in the see your DR sooner rather than later for a check and maybe some antibiotics

hope this helps

xx yogababy