I've had it with all of my pregnancies. I sit down for 5-10 mins and take some deep breathes, which sometimes helps. Mine is usually triggered by queing in shops, standing for long periods and getting up too quickly, so I try to avoid them. It's just your body coping with the extra strain of pregnancy. It may be worth mentioning at your next appointment as it can be a sign of other things if accompanied by other symptoms, but it is most likely nothing to worry about.