Pressure in pelvis and bum

Hey ladies, I am sorry if this is TMI! But I am really struggling with pressure in my pelvic area and now it’s even in my bum. My baby is 97th percentile for size at the last ultrasound and I typically feel movement in my pelvic area. I think he’s sitting low, and with his size, I feel like this is probably normal? But my friend mentioned that it sounds like pelvic girdle pain and that I should mention it to my doc. She said I may need to see a PT. Anyone experienced this? Is it urgent or can it wait until my next appointment. It is definitely uncomfortable but bearable.