Left labia swollen

What is causing my swelling on my left upper side labia?! I thought maybe Bartholins Cyst, but that seems to be closer to the vaginal entrance. My swelling is higher up. It’s painful and itches. Any idea? I’ve circled where it swells at. It comes and goes and only stays for a couple hours.

Edit to add that I’m almost 30 weeks pregnant and it’s been off and on swelling through my whole pregnancy. Never happened before I was pregnant