Who am I?

In order to save space, I have about 2 or 3 "seed pots" where I toss random seeds in the hope that they will eventually germinate. Normally when I see something sprouting, I just dig around and figure out what seed it came from and voilà I know what the plant is. Unfortunately I occasionally have a seedling that I can't place. I've been growing the plant below for about a year but I have no clue what it is. Any suggestions? It is vine-like and seems to be herbaceous. The leaves are compound with three tear drop/lanceolate leaflets with smooth edges. Really, any suggestions would be quite welcome.