This is going to sound silly but it's driving me mad!!
When I got pg I didn't know my LMP date as I had messed up my pill twice and only had one definate and one dodgy period. I know that the date it 'happened' was 19th July (I know, very sad! )
So...from this, i worked out my dates to be due on 10th April and started counting my weeks every Tuesday according to that date.
Since then I've had a whole host of other dates suggested by scans, doctors, midwives etc until they finally agreed with me and gave me a date of 12th April.
It now gets confusing when the midwife says 'so what week are we now?'
27 weeks now.....right?!?!?!
(I know it's not rocket science but they've confused me so many times!!)