So I'm not sure how to tell if I'm having contractions

Jo
I'm 24 weeks 4 days...last night I started getting a pain on both sides by the hip bone area, it's been getting more intense but it's not like horrid or anything more uncomfortable...I've never had cramping with my periods, I have not seen my mucus plug come out yet but heard u could lose it and not even know...I've had my appendixes removed and it feels like the start of that pain...it doesn't change with movement or food or water...I also have a uti but I never get pain with those...I'm not sure should j be worried?