As far as I can tell from the pictures, it looks like a wildflower called Bouncingbet. Clusters of these ragged-looking, scallop-tipped flowers form roadside gardens. The flowers are pink or whitish, sometimes with double petals; the leaves and stems are smooth. Bouncingbet is one of the many aliens from Europe that have taken over our roadsides and waste places. Call them weeds if you will, but they lend beauty to the otherwise drab and disturbed soils. Flowers in conspicuous clusters at the tops of the stems; about 1 inch across with 5 petals, and with base enclosed in a tubular calyx about ¾ inch long. Found along roadsides, in waste places, and on ditch banks. Originally grown in gardens as an ornamental, from which it has spread. In pioneer days, used as a soap substitute, the stems and rhizomes making a foamy solution when bruised in water. Hope this was helpful. Feel free to contact us again.
Another option to the identification of your weed or wildflower is that it could be a Campian. Check this site: http://www.gardenorganic.org.uk/organicweeds/weed_information/weed.php?id=94