Surprise before starting my cycle

I always hear about these stories where someone get pregnant naturally while waiting for an Ivf cycle. It’s never happened to me before.. in fact I’m 35 and have had unprotected sex for 10 years and tracked ovulation for 5!!! And never gotten pregnant. Ever.

I have two kids which resulted from 7-8 cycles of Ivf.

I was waiting for my period this Friday (I had taken Lupron and on letrozole to prepare for à get cycle) and couldn’t sleep one night and tested for fun and I’m pregnant despite having taken those!

Wtf!!!