I have been trying to get pregnant for a few months now and I took an at home test this week that came up negative. However, my breast are leaking white discharge.

Lactating when not pregnant can be caused by a range of things. It could be something as simple as stimulation triggering it. It could be an hormonal imbalance. It could be a side-effect of certain medications. It could be related to an underlying health problem. Sometimes it can be hard to determine any cause.

I wouldn't worry unduly but I would get it checked out. As you are trying to get pregnant it would be good to rule out any medical problems and maybe get tests regarding your hormone status.

And of course there's always the possibility the test was wrong.