Im 38 weeks preg and gettin vry bad pains..?

it started last night and stil they havnt gone, i havnt been able to sleep cause i cant lie down. i've got pains in the lower part of my body that seem lik very bad period pains that go around all the way to my back. it rly hurts when i walk and in fact i cant take more than 5 steps without havin to bend down. i dont have a show or waters didnt break so i dnt tink its anytin to do with labour, could it just be cos the baby is dropping? it is my 1st pregnancy so i'm not rly sure wat to expect, any advice would be useful..