Stomach ache

Jessica
Hi all,
I'm currently 36 + 3 and for the past few days have experienced a really low period style cramp all along my lower stomach. It's the sort of dull ache that tells you you've just come on! It's a continuous ache which comes and goes during the day but sticks about for hours. This is our second baby but I can't remember this with the first! Any ideas? Do you think I'm close? DD1 was 12 days overdue!!!