I’m 40 wks and leaking water

So I’m 40 weeks today and I’ve changed my underwear twice now because I’ve wet them but nothing exaggerated, little by little.. yesterday my dr. Checked me and I was almost dilated to 3.. but was not feeling pain at the time so sent me home and told me as soon as you get contractions or your water breaks, come back. So I’m not sure what I should do, I’m having lower back pains .. any advice?? Thank you