How accurate are dating scans. My lmp was 31st March. I was pressured into sex on 6th April. This was protected and he did not ejeculate. I was also still bleeding. On 9th, 10th and 14th April I had unprotected sex with my husband. Going by my dates I should either be 11+6 weeks or 11+2 weeks I had a scan yesterday and they put me at 12+2 this would mean I conceived on 5th April when I didn't have sex and was still on my period. I don't know what to do