How can I speed things up?

Megan • I am pregnant with our first child, a boy, due May 31st.
40 weeks and 3 days now. 2cm dilated with inconsistent contractions. My doc did a membrane sweep yesterday. 
I've been walking, drinking red raspberry leaf tea, evening primrose oil, and even tried sex. 
These contractions don't really hurt, a little uncomfortable/tight but it's hard to tell how frequent they are coming as I barely notice them and have no back pain. They must be doing something if I am at 2cm though, right?
Any other suggestions on what to do to speed things along? Does it sound like I am close?