Some symptoms to keep in mind that may occur during the egg freezing process are heightened emotions, extremely tender breasts, and/or more intense lower back pain than normal.
Aside from the swelling associated with water retention, the ovaries grow and swell, potentially leaving a “heavy” feeling in the lower abdomen. There are a few reasons we swell. Imagine getting your menstrual period and amplify that ten-fold (or more for some). Some women are generally less apt to swell and some more. The trend may depend on your general monthly tendencies. The number of eggs that will be ready to be harvested/“retrieved” can also play a part in how swollen you get during the procedure and after.
Something to understand and educate yourself about is hyperstimulation (also called: OHSS or ovarian hyperstimulation syndrome). This is a situation in which the ovaries become more swollen than normal and can be very painful post-procedure. A few weeks of recovery would be in order.