so throughout my pregnancy ive had around 5-6 scans.. and im expecting more to come due to awkward baby.. but from scans week 5,6,9 & 12 weeks my due date changed.. when i went for my 20wk scan it stayed the same as the 12wk one.. when i work it out from my LMP i should be 2 days ahead.. but a friend of mine seen my bump picture and said are you sure your not further along?.. can the hospital be wrong?