u/Curious_Snail_

I bought and planted a clematis (or so I thought) and this started growing so I trained it on the trellis. It hasn't bloomed and it's the 2nd summer, and it is spreading and sprouting on the lawn nearby. I'm starting to doubt it's a clematis. Is has thicker branches and hasn't bloomed.

Can anyone please help me identify it? Google images was no help.