dip at 9 dpo is this bad ???

Roslyn • Currently mummy to 3 beautiful girls currently ttc rainbow baby 👶🏻🌈🌈🌈👶🏻 x after 9 months of ttc our rainbow 🌈 baby is cooking away nicely due April 9 th god is great ❤❤❤
Hi could anyone take a look at my chart and tell me if this dip is a bad sign does it mean af is on her way also had a mild headache since this morning any advice would be grateful not looking no started charting thanks 🙏