Is this normal at 22 wks?

[oinkyoink]

I am 22 weeks preg and trying to work out if my situation is normal.

When I have go out and have been walking for an hour or so, my lower back starts to ache a lot and I get cramps in my lower belly, under bump. I'm just wondering if this is normal or if I need to get checked out. I had early contraction with last preg at 30 weeks and am scared it will happen again. However if it is normal, and others are feeling this I will know I am not overreacting.
Thanks

Im 27+4 and get pain under my bump when I'm walking, its like achey, sharp pains.
I saw the midwife on Wednesday and she said its nothing to worry about just everything rearranging when I walk.

But do see the midwife if you feel worried, it will put your mind at rest x

I get sharp pains in my lower belly. My midwife advised me to do the stomach exercises/stretches reccomended in the physio seminar and they help.