I would recomend a 7 week scan, we were given one because we had fertility problems i think the ivf dr didnt actually think it was possible that i was pregnant naturally the dr wanted to check the pregnancy was in the right place.
It was amazing, I was sobbing and sobbing it was so emotional, for me i had lost faith in my body and I didn't beleive i was actually pregnant till i saw the little flashing hb on the screan.
That very first scan was by far the best scan i had, it was amazing :)
Also we had a scan at 10 weeks to check the baby had grown as we were flying to the UK and i wanted to tell my family the baby news, the difference in just 3 weeks was amazing, the baby had grown from a flashing blob to a real looking baby with legs and arms and a nose and everything!
my tip is if you do go for a 7 week scan have your camera phone at the ready to record a little video of the hb, you cant really see much in a still photo.
this was my 7 week scan (they said i was 6+3 but i wasnt)
then this was my scan just over 3 weeks later
if you have the money go for it! id opt for an early scan over nearly anything :)