33 weeks, cramping nausea diarrhea

Im 33 weeks ......last night i didnt sleep well and im usually up ever hour or 2 to pee... lastnight my back hurt really bad so i left our bedroom so i could rock some to ease the pain without waking my hubby... (3am).... at 4am i felt super nauseous and some cramping and baby moving! So went potty and it was diarrhea!.. after the craping fely better baby moved even more and nausea went away..... then...... 5-10mins later its all back and im back in the bathroom... its been like this for last 3 hours..... is this start of labor, should i be worried? what will help?