Sounds like vulval variscosites - varicose veins of the vulva (as CK said). They can be quite painful and will most likely become more so as your pg progresses (sorry!!). You can get special shorts designed to provide additional support to the area, but they are quite expensive. Rest as much as you can and keep your feet up. You can ice the area if you find it helps, it should help to constrict the vessels (make them smaller, but only short term) and provide some relief. Panadol might help also.

Get your ob/MW to examine you if it is very painful. They might also have some other good suggestions for relief!