Hope it's not early labour Fi, and I hope it's not prelabour that will go on and on too! Have you eaten anything that could make you a bit gassy? Sometimes wind can move around and be painful periodically. Perhaps drink some ginger tea or something that might help if it is tummy/bowel related.

It wouldn't hurt to ring the midwives. If you're really worried, they can monitor your belly to see if it's contractions or BH or whatever (can't they?)

Hope it eases up soon. The last few weeks are uncomfortable enough without pains like that.