I think this would be a really helpful article for you to check out Honorably Discharged: A Guide to Vaginal Secretions
. Having discharge that leaks through to your underwear is normal, albeit, annoying at sometimes. It is a natural thing for your vagina to be producing. That being said, what about it is concerning you?
I'd look through the article to see if any of the symptoms you are feeling match up with the descriptions listed. Unless you are worried about it being an infection, in which case seeing a gynocologist would be a good idea, there is not much you can do to control it. Some people use liners in their underwear to deal with it. And it may change in amount or frequency overtime.
I hope this helps!