Earlier than thought on scan !

Feeling worried recently had a bleed got checked out and had a scan by dates I should have been 7 weeks but on my scan I was showing 5 weeks I'm returning in just over a week for another scan and I'm worried that history is repeating its self from a previous miscarriage. I'm feeling sick and my breast still hurt has anyone been through this at all if so any wise words or advice ???? Thank you in advance.