weight loss question

hey everyone,
what is your experience with initial weight loss when beginning tri training? I have been training for about 4 weeks now, 8-9 workouts/week (3 of each). I started with 15 min. of running, now I'm at 20; I swim for ~45min-1hr (1300-1800 yds), I started on the bike at 30 min and now am up to 40 at about a 15mph pace. I feel fantastic, although somewhat tired after the second workout of a "double day", and there are muscles that I haven't seen since highschool popping out all over my legs and arms and back. I eat a really healthy diet, hinging mostly on getting 5-7 fruits and veggies/day (I find that I don't have a lot of room left after that!) and have been focusing on staying really hydrated,moreso than before. Here's the problem- since I started tri training, the # on the scale has not changed. The optimist in me wants to say this is because of muscle gain... I do notice that my pants are looser, and my husband says my butt is smaller, but I would really like the scale to confirm! Has anyone else had a similar experience? I am about 20 lbs heavier than I would like to be.
Katie