I'm 33 weeks pregnant now for the past two days, my baby is really pus…

I'm 33 weeks pregnant now for the past two days, my baby is really pushing down and this morning there was some mild lower back pain that came and went. My tummy would contract and feel very hard. Could it be labor? I was at the hospital on Saturday, the gynecologist did a scan and said everything is fine. What could cause the pushing and pain?