Wild violets, Viola species. These tend to throw their seeds around easily, with new clumps springing up all over. Or you could try transplanting after flowering. (there's some clover mixed in there as well but the purple flowers are violets :-))

The clover is probably Trifolium repens which will have pinkish white flowers later in the year.

I agree with gardengal...wild violets.

Gunnysack

The sort of heart shaped leaves are the wild violet leaves.

Here is a link that might be useful: photo of clump of wild violets