You can start leaking anytime, I was lucky and didn't leak until after I had him but with some people it can start early

your leaking colostrum (spell check) lol its totally normal

I know this may be tmi lol but I have like this clear stuff coming out.

I've been told that some women don't lactate till after the baby. And some women do around 36 weeks.

after birth usually, some women may start in their last months but it is usually after birth, say 4 days after delivery.