Urgent Care or OBGYN or L&D?

I am currently 35 weeks. Tonight I noticed a hard area under the skin on the inside of my knee/lower thigh. The surface area of the spot is about 1.5 inches. My husband felt it and said he thinks it’s a bulging vein. When I first felt it, it felt more like a bump but now it feels like a firm flat surface. It is slightly tender when I touch it, but otherwise no pain. I can see a vein in that same area if I shine a flashlight on it.

I have some varicose veins on the backs of my knees, but none in this specific area.

I’m not sure what steps to take - should I go to an urgent care with ultrasound capabilities, call my OBGYN, or go to L&D to be checked out? My big concern is a blood clot. There’s definitely something there, I’m just not sure what it is.

I have been dealing with off/on swelling in both ankles/feet for several weeks now.