braxton hicks again !

I had a very stressful few days and started to get little tightening yesterday it got worse and I was up regularly during the night they stopped untill just and I've just had another rather painful tightening what hurt all down my thigh , my question is at what point with braxton hicks should you get seen ? at what point do you start to worry its more than that ? I'm 23 weeks and prone to early labour I've had 3 children early , my waters went at 29 week's last time and I did have a bit of discharge the other day which was brown tinged although not enough to worry me and my baby has been moving regularly like always too .... so what do I do ?