The first official day of your treatment cycle is the day you get your period. (Even though it may feel like you've already begun with the medications you've started before in step one.) On the second day of your period, your doctor will likely order blood work and an ultrasound. (Yes, an ultrasound during your period isn't exactly pleasant, but what can you do?) This is referred to as your baseline blood work and your baseline ultrasound.
In your blood work, your doctor will be looking at your estrogen levels, specifically your E2 or estradiol. This is to make sure your ovaries are “sleeping," the intended effect of the Lupron shots or GnRH antagonist.
The ultrasound is to check the size of your ovaries, and look for ovarian cysts. If there are cysts, your doctor will decide how to deal with them. Sometimes your doctor will just delay treatment for a week, as most cysts will resolve on their own with time. In other cases, your doctor may aspirate, or suck, the cyst with a needle.
Usually, these tests will be fine. If everything looks OK, treatment moves on to the next step.
