If it’s already leaking out, you can definitely collect it by using a nipple shield or a milk collector cup, but don’t squeeze any out manually x
Seconding what Abi has said — absolutely fine and great to collect any drops that are coming on their own! It’s manually expressing that you want to wait for, usually from around 37 weeks is safe but best to consult with your midwives before beginning to express xx
I contacted my midwife as I’ve been the same from 27 weeks She said to wait until 37 weeks as it can bring on labour!! But she said it’s a fab sign!