Pelvic pain/pressure at 31 weeks pregnant...?

I am 26 and 31 weeks pregnant with my first baby. For the past 24 hours I have been experiencing quite intense lower pelvic pressure and uncomfortable pain. There have been times when I could not sit or had to stand from sitting. I have noticed that I have also got internal haemorroids which could be adding to the discomfort? It has been that painful at times that I have 'moaned and groaned'. I am not sure if they are Braxtons or not? I wondered if anyone could tell me what this discomfort could be? My next midwife appointment is 6th June x