How do you know it's contractions?

Brittney • *Expecting Baby Boy*
Hi ladies! So I've been struggling the last few days with the pain I've been feeling and I'm not sure what it is. It feels like menstrual cramps down low in my abdomen and it hurts for anywhere from 5-15 minutes at a time. My baby is active during this as well so when she kicks or moves it feels SO tender and painful! I can't figure out if the cramps are contractions causing her to respond or if her movement comes first and the cramps come in response to her. I hope that makes sense! This has been happening on and off for a few hours a day. This is my first baby so I'm just struggling with knowing what's going on and when to be concerned. Thanks for your advice!