As Sally said, you can get them at any stage.
I had none with my first PG, my second I had them from about 36 weeks, my third a little earlier & this time around 22-24 weeks I think , although in the last couple of weeks they really picked up in intensity.
The last couple of weeks they were so painful / uncomfortable & regular for hours at a time, when i eventually started labour I didn't recognise it as labour for a few hours.
I know it's not much help! but everyone is different. Sounds like it could be BH in your case HTH