Ahh logistics

One more thing I need advice on...I'm going to have to talk to my supervisor about taking time off work to travel for my cycle. The doc wants me in town for the last 4 days (I think) before egg retrieval. And then I'd stick around after to amount to a total of almost 2 weeks. I'm not as concerned about getting it "approved" or what to do (FMLA, or voluntary time off, etc.) as I am about what to say as to why I need this time off. A gal on my team recently had a medical issue and my supervisor was very supportive and the whole team rallied around her. But it's so different dealing with this kind of stuff. Plus I'm a little gun shy about opening up about this at work. During my last cycle, my old supervisor appeared to be very supportive of me...I even had to cancel a (pointless) business trip to stay in town for injections. But then a different supervisor overheard her BEFORE A STAFF MEETING talking about my difficulties conceiving (which was all speculation, I might add, as I hadn't told her the real deal) and it got back to me. Obviously, I was LIVID. I had expressed to her that I wanted to keep this confidential and then she blabs about it in a room full of people??!! I was ready to report her to Ethics (cuz I am so much a "this is right, that is wrong" kind of person) but laid off cuz I figured I had enough to deal with. Instead, I involved a higher up who was very sympathetic and got me moved to a different (but not current) supervisor (and I ended up doing more of the type of work I wanted to anyway so it worked out). But it's always bothered me that she got off scott free with no one (but me) knowing how ridiculously unethical she is...hopefully this rant made sense! So even though I LOVE my current boss (she's about my age, has two girls, struggles with being a working mom, we've got lots in common, shared political views) and she appears to be a very thoughtful, compassionate person, I'm not sure how much to share. If I say I'll be going out of town for medical treatments, then she'll ask if I'm okay...I'll have to say yes, it's not life threatening? That sounds dramatic but vague. Do I say it's female stuff? Arrgh, this is going to be hard for me cuz I hate to lie (even if it is by omission). What if I elude to baby stuff and again I don't get pregnant? It'll just be another person to feel humiliated in front of. What if she does leak it? I don't want to chance our relationship being ruined. How do you handle this out of town business? I'm at a loss.