Rai, for my IUI cycles I'm doing something similar to the antagonist IVF protocol and I start stims on CD2. If you're doing a long down-reg protocol you can delay starting stims. My first IVF we had to delay starting stims by a week because my FS was on holidays and my outcomes were similar to all the other cycles where there was no delay.
Best call your Dr to discuss the timing. Seems crazy that they'd bring up those requirements at this late stage. I'd be right royally peeved! Can't say I've ever heard of anyone needing those tests done before starting IVF. Is there a particular reason she wants you to do them?