TMI Advise please?

Georgina • Mummy to a yummy 🌈 baby boy 27/07/2016. Preemie 🌈 Twin boys 30/03/2019

I'm currently 24w 6d with modi twins. I know pain and discomfort is to be expected. but when do I worry? I've the last couple of days I've been getting very small amounts of yellow jelly in my knickers, it doesnt smell, I'm not itchy or sore. The pain and pressure in my pelvis is becoming unbearable and so is the bottom of my back. It feels like I'm going to snap in half. The Braxton Hicks are intense but they're not regular so don't think they are contractions. My cervix was 2.4cm last week (at 12 weeks it was 3.3cm) however although this is not my first baby I've never experienced anything like this nor labor as I had a planned c section with my first. Is this normal for twin pregnancy?