I know you are frustrated, but you have to give your body time to "rest" in between losses, especially big ones! I lost 8 pounds in 2 weeks, and none this week but that's o.k. because the body needs breaks to "catch up" before losing again. The weight will continue to come off if you are faithful, hang in there!
As for the other question about phase 3, you really do need to talk to the dr about that one.

you are doing great! Hang in there and good luck with the IVF.