Blood Tests

Tina • After many years me and my husband are away to start a different journey IVF
So today I finally got my appointment at the doctors and they are going to do some test to see if everything is ok as we have been TTC for 5/6 years.
So he told me that I have to have my blood taken as certain parts of my cycle and he needs them to be taken Monday.
This is where this issue is...
My doctors is booked up till December! So they are sending me somewhere else to get it done but I have to sit and wait to see if they can fit me in so I could be there for half the day and I have work, what do I say to work? I'm never off sick and don't want to tell them why I'm going as I don't feel I should have to tell them!
Any advice would be a big help as I'm driving my husband crazy with "I could say" "they will never believe that" ✨✨