Hi. I went to GP about infertility this time last year. I'd just got a job offer starting in September but just couldn't put it off (age!). I never have time of work and dreaded asking for it as a new member of staff but just had to get over it! I'll always drag myself into work rather than make that call in sick.
The first few appointment were very spread out: October - hycosy, Feb- follow up, March/ April form signing/ treatment schedule. I managed those by stating 'gynae issues' and booking as many as possible in holidays.
I think it will completely depend on your job how much it's going to affect your work. I'm a teacher so can't book any time off. I am also supposed to show proof of appointments to request paid leave. I photocopied a couple of appointment letters and tipexed the 'IVF' bit!
I've got egg collection tomorrow and I eventually told my boss about a month ago because there was no way I could have kept asking for time off without them knowing why. They've been great and are letting me go to appointments paid which they don't have to. Luckily my scans were last week during the holidays. I read some posts were people said they managed to fit them in before work, but I have to leave home at 7.15 for work so that never would have worked for me.
I've also read of some people booking one or two weeks off for treatment so that could be an option for you. However I found that it's all the random appointments before that caused me more stress in having time off. Plus it's never certain exactly what days you'll need- scans might show that things might need to move around.
I would definitely just go for it. I know I do a really good job in work and a few appointments and days off is nothing really (even though I really stress about it) and if the IVF works then you'll be too happy to care about telling work.
As I say- my boss was great. Been great about time off and says a maternity leave would be a small (positive) part of my career in the school. I can imagine not all bosses would feel the same (and being in a probationary period did worry me) but I think there's a time when you just have to do it for you.
Good luck