Cramps every evening


I’m 39 weeks and for the last week or so I’ve been getting period cramps in my back. Mainly in the evening but occasionally day time. They are manageable but go away over night! I going to bed thinking it’s time and then nothing! With my first I was induced at 40 weeks and had not an incline of labour / cramps until the meds kicked it and they were really strong! How long could this last? I live in UK so they don’t check for dilation / cervix etc here but he is head down. Cheers