Anonymous post question

Annon post…

So not to be TMI, but when my boyfriend “squeeze” my nipple , a big whit discharge came out of it (as if it was milk ) , I have two kids in previous relationship, I took a pregnancy test and it says I’m negative ?
What could it mean if I’m not pregnant? We don’t have protected sex. He doesn’t pull out either anymore and we have sex at least 3 times a day.
Been with this man for a year, so he’s not a stranger stranger to me anymore, but I’m lost if I’m not pregnant what could this mean?