7DPO and no darkening of the nipples?

Hey ladies, I’m 7dpo today and so far I haven’t had any soreness in the nipples or breasts and no darkening either. Shouldn’t that have happened by now if I was pregnant? If not, when does it happen?

With the first pregnancy I was super sore straight away, like couldn’t even wear a bra and my nipples were so swollen!

Any advice would be amazing x