When to be worried?

I'm just about 31 weeks. I keep getting woozy with pain in my side, and I'm not dehydrated, I had proper breakfast and lunch. Laying on my side or putting my feet up doesn't help, and a mild temperature shower didn't help either. I feel achy down there like I have a bad period but I'm not. No bleeding, but frequent urination where I feel a bit crampy when I pee.

Do I need to be concerned? My mom isn't answering her phone and my obgyn only has emergency hours on the weekend where they charge double.

Update: it turns out I was having preterm labor, and was in the hospital until they could force the contractions to stop. If you have a feeling something is wrong, do something about it.