Expressing milk while pregnant??

Okay, I’ve read and seen everywhere that nipple stimulation can bring on contractions... i wanted to start expressing early as I’m leaking colostrum and wanted to save it. I put a post up on this about it a little while ago and asked if I can do it safely and all the replies were of women telling me not to and that one woman’s doctor had told her it can cause preterm labour???

I asked my midwife the other day and she said it doesn’t...... I’m so confused... I know she’s a health professional but EVERYWHERE else says different... anybody have any experiences or any information about this?

Thanks ☺️