Well, you are 38 weeks...could it be contractions of some sort? (I wouldn't know, I've felt nothing )

Skorpy asks some good questions..if they are spaced out, how far apart are they? Could you call your hospital and see what they think?
And good on you for still eating, just in case it is labour, and then you might want the energy. If you can keep anything down at all...

Well, I don't know exactly how you're feeling or what's going on, but if that was happening to me, I'd be calling my birth centre and seeing what they thought.
All the best!