Sarah,
In my 1st cycle I had spotting every single day that i was on the pill...all 30 odd days. The nurse said it's a low dose pill and my body was just trying to get used to it (then real AF was 8/9 days late). In my second cycle i had spotting every single day again (aargh!) and then AF came 7 whole days early - before i stopped taking the pill. Even that was not a problem, apparently, i just kept taking it and carried on as normal. (i was a 28 day regular before IVF!)
I would ring them and let them know. I have a fabulous nurse who gets lots of 'crazy lady' calls from me, if it makes you feel better! Sometimes, they will just make a note of it, and the more info they have on you and the way you respond - the better.
GL
Jo