I would ask the nurse if you can postpone for a month, to be sure you are not pregnant now. Not that having a little blood is any very clear indicator, but you would like to be sure. It won't kill you to wait a month to start your birth-control pills, I assume.
I did acupuncture to support my IVF and thought it was very helpful. It was recommended by my RE.
Thanks for your comment. Did a blood test and it was negative and hcg level was 2.
Sounds like you can perfectly appropriately start the bcp's. Good luck with your IVF.