Feels like something is coming out?

Hey so I’m currently 37+3 and I feel like something is stuck/wanting to come out of my vagina. I haven’t lost my plug yet so thinking it could possibly be that? The only way I can describe it is like an air bubble sort of pressure. I can feel it when I relax (I’m currently laid in bed), but can feel it more when i tense.. any one had this before?