Hi,
From what I've heard it's not always easy to tell what you'll end up getting at EPU. I had 30 follicles at first scan then 32 but only managed to retrieve 10 eggs, 5 of which were mature enough to fertilise. I know of someone who had much less follicles at her scan but got lots more eggs on the day of pick up (have a look at the thread called 'First Scan Date) Then I have a friend who over-stimulated with 40+ follicles and got no viable eggs.
Seven sounds like a good number and it may increase before EPU. Your chances of developing OHSS are also reduced with this number.
Good luck with your cycle.
Maggie