Book leak not pregnant

My friend has taken 2 pregnancy tests 2 weeks apart both clearly negative. shes also had her period at her normal time tho short. This morning she woke up with a soaked shirt from one boob. She’s never been pregnant. It had No smell or color. Google is coming up empty. Anyone experience this or heard of it?! She has a gyno scheduled and thinking of moving it up, but I’m trying to reach out for her.