Cramping at week 33, normal?

[macdat]

I've had period pain like cramps since yesterday. They were constant all day yesterday and today they've been there most of the day but coming and going.
Is this normal at this stage or not? They are quite painful, but I'm not doubled over in pain like i assume labour should be like.

I have been having these for the past week but they come and go with my Braxton Hicks. Could it be these causing it? Do you feel tightening at the same time as the pain?
As far as I know BH shouldn't be painful but mine are intense and do take my breath away sometimes.
If in doubt always ring midwife/DAU just in case though