Pain is confusing...

I'm about 18.5 weeks preg with my first. Occasionally I get pains, like cramps. Just like period pain. I know some pain is normal because u are growing. But last night I was walking around the shopping centre for quite a while and got horrible sharp pains in my stomach, in the left side. They almost took my breath away and lasted about half an hour. After sitting down in the car on the ride home for 20mins i was better.

My question is How are you supposed to know what pains are normal and what pains to be concerned about?????????????
Anyone else have pain on one side???

I had to walk for a long time with a heavy book bag today, and now Í'm hobbling like an 90yr old woman, if someone offered me a zimmer, I'd totally take it! I remember reading that if the pains are consistent, and don't go away when you lie down for an hour or so, or increase in intensity during that time, then give someone a call. It sounds like you walked too much, take some time to chill! I occasionally get really sharp pains, I think they're round ligament pain, but as long as it goes away - tis all good.

Sometimes you can get gas building up in the tummy which is very painful.
Pain down low tends to be ligaments etc.