I know exactly how u feel! When I was pregnant with my youngest daughter, I started feeling this way at probably 6 months. I has asked my dr abt it & he said it was bc her head had actually developed in the birth canal so it really was lower than most mom's felt. I couldn't squat or anything bc I had the fear she fall out lol. Logically I knew this couldn't happened but as I pregnant mom anything is possible:D so for the rest of my pregnancy I just had to avoid as much as I could that would bring on the feeling. In the end when I did have her- from 1st pain to cutting the cord was 43 minutes! Fastest on record for my doctor lol
your baby is probably dropping some….I'm sure it's just weight of the baby too…I don't remember how it was with my DD but if you are concerned about your Dr can check you but I'm sure it's a normal thing