31 weeks, preterm labor questions

Alexa • Micah Tyler born 08/31/17 💙
I have had a good second half of pregnancy and just had an ultrasound Sunday where everything (cervix, fluid) looked good. My fundal height was measuring 3 weeks ahead. But I haven't really had cramps or anything just alot of pelvic pressure and I could tell my boy had dropped about a week or so ago. Tonight I bought a birthing ball to start helping with my pelvic and hip pain and I used it twice. I was sitting on it slightly bouncing a little while ago and I had two contractions a few mins apart so I got concerned and stopped... when I got up it felt like I peed myself a little. I went to the bathroom and it was clear, not yellow. It also felt like I was dripping for a minute. So I've been drinking water and sitting in bed for a while and I'm having overall cramps. Not like period cramps but more like when you really have to have a BM. It hasn't gone away yet and I'm getting nervous but I really feel fine? Surely there's no way that sitting on a birthing ball would send me into preterm labor right?? I'm going to go to L&D if it persists through the next couple hours but I'm definitely not prepared to have a baby yet.