Did I just have contractions for full bladder?

Ok I’m 16+3 with twins and I’ve been drinking a lot of water and I’ve had to go a zillion times. I was laying on the couch saving podcasts and was really into reading about one and really had to pee. My uterus started to feel weird way down low and was almost pulsing? Was this contractions because I had to pee so bad? I went and felt much better, note to self, go pee immediately. It was super uncomfortable.