Hi Lisa Jane,
It might be the implantation bleeding. I'm 10 weeks and had bleeding on Monday so know exactly how you are feeling. I rang a midwife and she asked if I had any pain, cramping etc. She wasn't overly concerned when I said I hadn't she suggested it might just be the placenta implanting, the bleeding went again. I think it's pretty common but go and see your GP if it's bothering you alot. Hope that helps, thinking of you.