Charlee, I had a similar problem when I went on the pill before starting IVF...

Slightly different case to yours, I hadn't had AF for well over 100+ days, but a blood test showed I was ok to start taking the pill, but after about a week I developed break through bleeding.

At first it was just spotting, and the nurses said this would be ok, and wouldn't cause any problems at all.

Unfortunately, because my instructions were to stay on the pill even though I was bleeding, it all got worse. It was mainly because it had been so long since my last AF, not simply because I'd kept taking the pill... In the end I was very nearly hospitalised and had to take other drugs to try to control the bleeding because it got so bad.

I don't want to scare you, but you will be ok as long as it is just spotting... if it starts getting heavier, you really do need to make a fuss with your clinic because you really, really don't want to end up where I did!

Good luck with the IVF cycle!

BW