Are you pregnant or had a baby?

No

I mean not that I know of

I am 20 years old and my breast leak . What is wrong

If you are pregnant or have recently had a baby, your breasts may leaf even if you did not breastfeed.

If this doesn't apply, it is likely that your hormones are out of balance. You can see a doctor to get those checked.

Also, have you been taking medication for indigestion? There are a couple of over-the-counter medications which have a side effect of making you produce milk. It even works on men!