Braxton hicks

Laura • Laura
Well I'm 21 weeks and definitely getting Braxton hicks 3or4 times/occasions a day.
Lasting 30-40seconds a day.
Every time I get them I normally have no more than 4/5 in the space of an hour.
I sometimes get slight pelvic pressure too. 
Are any other mums to be a experiencing this? Is it normal?