I am 35 weeks today. started leaking about 2 weeks ago. it can start happening at anytime during pregnancy even early on. it can also not happen at all until u are in labor. wouldn't stress over it.
most women don't get their milk until 2-5 days after delivery. the body producing oxytocin during delivery is what signals your breasts to start producing milk. you have colostrum for a few days before hand some even get that early. how ever it's no indication of a good supply or not. I started producing colostrum at 17 weeks with my daughter. I dried up for all of a week after we stopped breastfeeding due to a poor latch and then started producing again once I got pregnant again (daughter was 3 months old when I found out). anyways my actual milk didn't come in until the day after she was born. you still have time mama! don't sweat it:) when I drink a ton of water during the day I really notice leaking so maybe you are not as hydrated as you think? maybe baby is pulling more from you than you realize.
I was concerned as well but my doctor said that some women don't get their milk until after baby is born. It's there but might not leak. Everyone is different :)