Hay,

my instructions ,us on monday, say pee about an hour before and then drink 4 cups so 800ml -1lt and not pee again, now if you ask me that is a form of torture, but for the 13 week scan I had I tried, now while waiting for the scan, I just went nup, I can't wait any longer and if I don't go now I might pee my pants, so I went, and then downed about 2 cups of water before the scan, no complaints from the sonographer.

I think the best thing is to just make sure you stay hydrated, and take some water to the appointment, 'cause you will probably wait for 15 to 30 minutes for your scan anyway.

Enjoy your 20 week scan. I almost cry when I see that baby, and the heartbeat, and then they move, and you can see the fingers & toes, oo it makes me giddy thinking about it.