38wk and 4days pregnant, am I in early stages of labour?

Hi, I am 38and half wk pregnant and have been having so much pain in my lower back and also sharp pains in the bottom of my stomach, I have been having funny twinges since yesterday and could not sleep last night, baby is still moving norm, but have to keep changing underware as I have leaked a few times without even realising it. Is it starting? Thanks in advance for any answers