Please wait for others to confirm what I am about to say, but I think that Prof Studd says it's OK to have a shorter 7 day course of Utro if you react badly to the progesterone. He suggests doing it at the start of the month. I guess, as a one off, taking it for only 8 days would be OK, so at least it would ease the timing with your new job (are you a teacher?). Weirdly, I was OK during the Utro days but had a horrible dip afterwards so stopped that regime and moved to a lose dose BCP instead (Qlaira) which helped. I am a similar age to you.
Hope tomorrow goes OK xx