So I’m at work and my back has been hurting really bad, and I keep getting sharp pains in my abdomen and it’s like I…

So I’m at work and my back has been hurting really bad, and I keep getting sharp pains in my abdomen and it’s like I keep getting an urge to “push”. If I tense up my ab muscles then it relieves the pressure. Should I call? I know it’s probably a dumb question but obviously this is my first pregnancy so I’m new to everything.