I would call your doc... I started having issues around 31 weeks. Mainly when stressed & with 3 kids (6 and under) running around that can be often. My doc got upset at me because I didn't go o the ER... I though as long as my water didn't break I was ok, but I also noticed that the baby wasn't moving like normal during my issues.
A few weeks ago we went on a long walk - the "cramping" got so bad that I couldn't walk during them. I got really scared cause I was only 34 weeks along... it took all day for them to go away, but the baby was moving a lot so I was instructed to stay home that time. Now I'm being told no more long walks after all I'm pregnant - lol.
I just hit 37 weeks on Tues... so I'm considered full term now. I joke telling my hubby that he is waiting till the grandparents are out of town the Father's Day campout we can't attend (doc orders) & then he will show up. Only cause it will be harder to find someone to watch the other kids this coming weekend - lol.
Anyways - my doc said to do what ever it takes to relax when the crampin/pain starts... lay down, put your feet up, take a shower or bath, read a book, watch tv, ect. Try to watch/tack the baby movement & see if you can get it to go away. If it continues, to call him & he would instruct me from there.
But I would talk to your doc about it asap... he my have different instructions for you. Mine just wanted me to get passed 36 weeks... since I was told from the get-go that with this being #5 - I most likely wouldn't make it to full-term and it would suprise them if I made it to 40 weeks. But we will see... like I said I'm at 37 now.
Good luck & congratz on the baby!