I am having pressure similar to you I'm almost 33 weeks. My doctor told me on Tuesday that the baby is very low and pressure is normal. As long as i don't have more then 5 painful contractions in an hour I am fine. But I have a desk job so it might be different for you. I would call the doctor and check with them
I would def call because all that pressure could be an emergency baby could already be opening up your cervix and you still have some weeks to go...its better to be safe than sorry...I hope you feel better soon
I mean 12 hour shifts and I'm not sure if I should be working before I see the doctor again.