Started BC for IVF

Kait • 💍 9.30.17. —> 1 👼🏻 —> 🙏🏻🌈 —->IVF round one December 2018

I’ve been on BC for my IVF cycle at the end this month for 3 weeks and 2 days, i started it on cycle day 3.. I start stims in about a week and a half, today I woke up with some spotting, my nurse told me I wouldn’t have another period until after Egg Retrieval which is schedule for the first couple days of December... should I be worried about my spotting?