In MA, what is this plant w/small purple flowers (5 sections) and stick-out yellow center called?

I have to do this project for school to identify the plants. It is fairly close to the ground, with small leaves that don't have smooth edges. They are not waxy leaves and the stem is fairly small but not tiny. It is early summer/late spring and some flowers are open and some aren't yet. It might possibly be a weed??? Please help me somebody!!! I've tried searching it on google but I can't find anything...