35.2 weeks, lots of pressure in butt

This might be tmi but I woke up with a TON of pressure on my butt this morning and it's just not going away. I'm sure with being this far along it's normal, but could this indicate that labor could be close? I was a pre term baby and the doctor says because of that my babycould be too. I'm a first time mom so I'm not really sure what labor signs to look for