Explaining IVF to boss

I already told her I would be doing it soon. she said that it’s not a problem and she will work with my schedule. I work 6am to 2:30pm from home. I have a lot of vacation time but i would prefer to save it for maternity leave. So should i just ask to change my schedule for monitoring days and then I will have to call out last minute when it’s time for retrieval and transfer?

Or should I just use My vacation time. By the time i have the baby (hopefully) It will be the end of the year and I’ll have a month of vacation time by then. Thanks for the help! It’s so hard to explain IVF to people that aren’t familiar